Manuals/T-LS

From ZaberWiki

Contents 1 Disclaimer 2 Precautions 2.1 Special Note 3 Initial Setup and Testing 4 Installation 4.1 Connection to a Computer 5 Control Through The RS-232 Serial Port 5.1 Examples 5.2 Data Conversion Algorithms 5.3 Sample Waveforms 6 Quick Command Reference 7 Detailed Command Reference 7.1 Reset - Cmd 0 7.1.1 Special Note 7.2 Home - Cmd 1 7.3 Renumber - Cmd 2 7.4 Store Current Position - Cmd 16 7.5 Return Stored Position - Cmd 17 7.6 Move To Stored Position - Cmd 18 7.7 Move Absolute - Cmd 20 7.8 Move Relative - Cmd 21 7.9 Move At Constant Speed - Cmd 22 7.10 Stop - Cmd 23 7.11 Read Or Write Memory - Cmd 35 7.12 Restore Settings - Cmd 36 7.13 Set Microstep Resolution - Cmd 37 7.14 Set Running Current - Cmd 38 7.14.1 Special Note 7.15 Set Hold Current - Cmd 39 7.16 Set Device Mode - Cmd 40 7.16.1 Special Note 7.17 Set Target Speed - Cmd 42 7.18 Set Acceleration - Cmd 43 7.19 Set Maximum Range - Cmd 44 7.20 Set Current Position - Cmd 45 7.21 Set Maximum Relative Move - Cmd 46 7.22 Set Home Offset - Cmd 47 7.23 Set Alias Number - Cmd 48 7.24 Lock Settings - Cmd 49 7.25 Return Device Id - Cmd 50 7.26 Return Firmware Version - Cmd 51 7.27 Return Power Supply Voltage - Cmd 52 7.28 Return Setting - Cmd 53 7.29 Return Status - Cmd 54 7.30 Echo Data - Cmd 55 7.31 Return Current Position - Cmd 60 7.32 Error - Cmd 255 7.32.1 Error Codes 8 Reply-Only Reference 8.1 Constant Speed Tracking - Cmd 8 8.2 Limit Active - Cmd 9 8.3 Manual Move Tracking - Cmd 10 9 Manual Control 10 LED functions 11 Troubleshooting Motion Devices 11.1 Data cable wiring diagram 12 Warranty and Repair 13 Email Updates 14 Contact Information 15 Appendix A: Default Settings 16 Appendix B: Device Specifications

[edit] Disclaimer

Zaber’s devices are not intended for use in any critical medical, aviation, or military applications or situations where a product's malfunction or failure could cause personal injury, death, or damage to equipment. Zaber disclaims any and all liability for injury or other damages resulting from the use of our products.

[edit] Precautions

Zaber’s motion control devices are precision instruments and must be handled with care. In particular, leadscrews must be treated with care. Axial loads in excess of the stall load, axial and radial impact, dust and other contaminants and damage to the leadscrew thread will reduce the performance of the device below stated specifications. Performance depends very much on the condition of the leadscrew. This protects the leadscrew from the environment. The leadscrew may be cleaned periodically for best results. To clean the screw, first use methanol to dissolve old grease and contaminants. There are plastic components that may be damaged by some strong solvents. A small amount of silicon based grease should be applied to reduce friction, backlash and sticktion. For vacuum applications we recommend NyeTorr 5300 silicon based vacuum grease available from http://www.nyelubricants.com.

[edit] Special Note

T-LS linear stages contain a spring which applies a light load against the leadscrew. Typically these stages are used in a horizontal orientation, and the only force experienced by the leadscrew is the spring force, which serves to keep the load on the leadscrew always in the same direction, thus reducing backlash. If used in a vertical orientation, the spring is not needed to reduce backlash since the load (the weight of the stage and whatever may be mounted to it) is always in the same direction by default. In fact, if the load is greater than the minimum spring force and less than the maximum spring force, the existence of the spring will actually introduce backlash since there will be a point in the stage travel where the load on the leadscrew changes direction. Therefore, when using T-LS stages in a vertical orientation, we recommend removing the spring from the stage. This can be done relatively easily using a small hook fashioned from a paperclip to slip the spring off its mounting posts and slide it out of the stage. It may help to fully extend the stage prior to spring removal.

[edit] Initial Setup and Testing

If you are unfamiliar with T-series devices, you may wish to perform a few simple steps to familiarize yourself with their operation. First you will need a power supply. If you ordered one with your device you shouldn’t have any problems. If not, you will require a power supply with output voltage between 12 and 16V. The power input accepts a standard 2.1mm center positive connector. Most 12V AC to DC adapters output around 16V under light current draw, dropping to 12V at their rated current. Some may output higher voltages and will not be suitable. The chosen power supply must also be rated to handle the maximum total current draw of all devices connected to it. When powering long chains of devices, we recommend connecting a power supply to at least every 3rd device in the chain to reduce the current through the data cables.

Once you have a working power supply, you can test the operation of your device. Try turning the potentiometer counterclockwise to home the device. When operating manually, you must home the device by retracting it completely every time you disconnect or turn off the power. You will not be able to achieve the maximum travel until you have homed the device. After the device retracts completely it will stop automatically and you can turn the potentiometer clockwise to extend the device. If you have a T-xxxx-S model you cannot control the device manually. Instead you must install the device on a computer and issue a home instruction.

[edit] Installation

[edit] Connection to a Computer

Connect the device to a computer as follows:

Installation
Step 1	Step 2	Step 3	Step 4

1. Plug the Mini-DIN to D-Sub serial adapter into your computer’s serial port and plug the device’s data cable into the adapter. You may need to use a cable extension to reach your computer. There is no need to power-down or reboot the computer. USB-to-RS232 converters are available if you have no RS232 serial port.

2. Connect the power plug of your power supply (2.1mm center positive) to the power connector of the device. If present, the green LED should light indicating the device has power (some devices may not have LEDs).

3. Install a program from the included CD, or download one from the software section of our wiki at http://www.zaber.com/wiki/Software . We recommend installing "Zaber_VB6_Demo_Advanced" to get started. Follow the instructions in the readme file to install and run the program. As a simple first test, try entering these instructions:

Renumber all devices                - Device: 0, Cmd:  2, Data: 0 
Home device 1                       - Device: 1, Cmd:  1, Data: 0
Move device 1 to 10,000 microsteps  - Device: 1, Cmd: 20, Data: 10000

To see the microstep distance for your device, see the specs page for that device on the respective product page .

4. Additional devices can simply be daisy-chained to the first. For long chains, a power supply should be connected at every 2nd or 3rd device. A renumber command needs to be issued after a new device is connected before it can be controlled independently from the demo program.

[edit] Control Through The RS-232 Serial Port

All T-Series devices use the same RS232 communications protocol. Your communications settings must be: 9600 baud, no hand shaking, 8 data bits, no parity, one stop bit. The yellow LED will light when there is activity on the RS232 lines. You may use this feature to determine which COM port you are connected to. We recommend using the sample Visual Basic program included with Zaber products. This program also contains source code that you can use as an example for writing your own custom code.

Important: The first time you connect a device to your computer you must issue a renumber instruction to assign each device a unique identifier you must issue a renumber instruction. This should be done after all the devices in the daisy-chain are powered up. In older firmware versions (prior to version 5xx) you must issue a renumber instruction after each powerup. In firmware 5xx and up, the device number is stored in non-volatile memory and will persist after powerdown, so you need only issue the renumber instruction when you add new devices to the chain, or rearrange the order of the devices, however it does no harm to issue the renumber instruction after every powerup. You must not transmit any instructions while the chain is renumbering or the renumbering routine may be corrupted. Renumbering takes less than a second, after which you may start issuing instructions over the RS232 connection.

All instructions consist of a group of 6 bytes. They must be transmitted with less than 10 ms between each byte. If the device has received less than 6 bytes and then a period longer than 10 ms passes, it ignores the bytes already received. We recommended that your software behave similarly when receiving data from the devices, especially in a noisy environment like a pulsed laser lab.

The following table shows the instruction format:

• Byte 1 - Device #
• Byte 2 - Command #
• Byte 3 - Data - Least Significant Byte (LSB)
• Byte 4 - Data
• Byte 5 - Data
• Byte 6 - Data - Most Significant Byte (MSB)

The first byte is the device number in the daisy-chain. Device number 1 is the closest device to the computer and device number 2 is next and so on. If the number 0 is used, all the devices in the chain will process the accompanying command simultaneously.

The second byte is the command number. Bytes 3, 4, 5, and 6 are data in long integer, 2’s complement format with the least significant byte transmitted first. How the command data are interpreted depends on the command. Complete details are given in the command reference on the following page.

[edit] Examples

• All devices renumber: 0, 2, 0, 0, 0, 0
• All devices home: 0, 1, 0, 0, 0, 0
• All devices return firmware version: 0, 51, 0, 0, 0, 0
• Device 1 move to an absolute position (command 20) of 257 microsteps: 1, 20, 1, 1, 0, 0
• Device 2 move to a relative position (command 21) of -1 microstep: 2, 21, 255, 255, 255, 255

If you are using Zaber’s demo software, you will only see 3 entry fields: Device#, Command#, and Data. The Device# and Command# fields accept integer values while the value you enter into the Data field can be signed. The value in the data field is converted by the software to 4 separate bytes and then gets sent to the device.

Most instructions cause the device to reply with a return code. It is also a group of 6 bytes. The first byte is the device #. Byte #2 is the instruction just completed or 255 (0xFF) if an error occurs. Bytes 3, 4, 5 and 6 are data bytes in the same format as the instruction command data.

[edit] Data Conversion Algorithms

If you are writing software to control Zaber products, you'll likely need to generate data bytes 3 through 6 from a single data value, or vise versa. The following pseudo-code can be used as a model.

Converting command data into command bytes to send to Zaber products

If Cmd_Data < 0 then Cmd_Data = 256^4 + Cmd_Data                                                'Handles negative data
Cmd_Byte_6 = Cmd_Data / 256^3
Cmd_Data   = Cmd_Data - 256^3 * Cmd_Byte_6
Cmd_Byte_5 = Cmd_Data / 256^2
Cmd_Data   = Cmd_Data - 256^2 * Cmd_Byte_5
Cmd_Byte_4 = Cmd_Data / 256
Cmd_Data   = Cmd_Data - 256   * Cmd_Byte_4
Cmd_Byte 3 = Cmd_Data

Converting reply bytes into a single reply data value

Reply_Data = 256^3 * Rpl_Byte 6 + 256^2 * Rpl_Byte_5 + 256 * Rpl_Byte_4 + Rpl_Byte_3
If Rpl_Byte_6 > 127 then Reply_Data = Reply_Data - 256^4                                        'Handles negative data

[edit] Sample Waveforms

If you are designing hardware to interface with Zaber products it may be useful to see some sample waveforms.

This image shows an instruction (top waveform) and a reply (bottom waveform).
This is a closeup of the instruction bytes. Note that the voltage swing of the instruction waveform is about +/-10V. This is typical of the USB to RS232 converter to which the device is connected. The instruction bytes are 0, 51, 0, 0, 0, 0 indicating the instruction: Device: All, Command: Return version, Data: 0.
This is a closeup of the instruction byte 2. The "S" on either end represents the start and stop bits respectively. The start bit is always positive and the stop bit is always negative. The bit sequence is Start, 0, 1, 2, 3, 4, 5, 6, 7, Stop. The data is output with the least significant bit first, so the byte shown is actually 00110011 in binary or 32+16+2+1 = 51 in decimal. It's a good idea to do a timing "reality check" whenever viewing a waveform such as this. The bit rate should be 9600 bits/second. The time scale in the image is 200 us/division. Since a byte consists of 10 bits (start, stop, plus 8 data bits) and the bit rate is 9600 bits/s, the duration of a single byte should be 1.04 ms (10/9600 seconds) or about 5.2 divisions at 200 us/division. It can be seen in the image that this is the case.
This is a closeup of the reply bytes. Note that the voltage swing of the reply waveform is about +/-8V. This is a typical output from the RS232 driver chip used in Zaber devices. The instruction was to all devices. Only a single device is present so there is only one reply. The reply is 1, 51, 252, 1, 0, 0 indicating the reply "Device: 1, Reply: Firmware version, Data: 508". The data is the last 4 bytes combined, with least significant byte first. In this case the data is 0*256^3 + 0*256^2 + 1*256 + 252 = 508. This indicates a firmware version of 5.08 since according to the instruction specification a decimal is assumed before the last two digits. The time scale in this image is 1 ms/division. As noted above, at a bit rate of 9600 bits/second each byte should take 1.04 ms. Therefore a 6 byte reply should take 6.24 ms. It can be seen in the image that this is the case.

[edit] Quick Command Reference

The following table offers a quick command reference for motorized devices running firmware version 5xx. For convenience, you may sort the table below by instruction name, command number, or reply number. Follow the links to view a detailed description of each instruction.

* The settings for these commands are saved in non-volatile memory, i.e. the setting persists even if the device is powered down. To restore all settings to factory default, use command 36.

[edit] Detailed Command Reference

The version of firmware installed on any Zaber T-Series device can be determined by issuing command #51. A three-digit number will be returned. Assume 2 decimal places (ex a reply of 293 indicates firmware version 2.93). This command reference applies only to firmware version 5.00 and up (the most recent version). For earlier versions of firmware, please consult the appropriate PDF user's manual:

T-Series Manual 2xx (PDF)

T-Series Manual 4xx (PDF)

Due to the addition of new features, newer versions of firmware may not be 100% backward compatible. You may wish to read the document Firmware History and Migration which outlines the changes that have taken place from one firmware version to the next and indicates what options are available if you wish to upgrade or downgrade the firmware on your devices.

[edit] Reset - Cmd 0

Instruction Name	Reset
Firmware Version	5.00 and up
Command Number	0
Command Type	Command
Command Data	Ignored
Reply Data	None
Persistence	n/a
Summary	Sets the device to its power-up condition.

This sets the device to its power-up condition. It has the same effect as unplugging and restarting the device.

[edit] Special Note

The position stored in the device prior to this command will be lost, so you must save it and reload it if it is important. All non-volatile settings (i.e. Device Number, Target Velocity, etc.) are saved and are not affected by reset or power-down.

[edit] Home - Cmd 1

Instruction Name	Home
Firmware Version	5.00 and up
Command Number	1
Command Type	Command
Command Data	Ignored
Reply Data	Final Position
Persistence	n/a
Summary	Causes a motion control device to back up to the home position and reset its internal position to 0.

Upon receiving this instruction, a motion control device will retract until its internal home sensor triggers. It will then move forward several steps to avoid accidentally re-triggering the home sensor during use. If a home offset has been specified with the Set Home Offset (command #47) instruction, the device will extend the additional distance specified. It will then stop and reset its internal position register, effectively setting the final position to 0.

[edit] Renumber - Cmd 2

Instruction Name	Renumber
Firmware Version	5.00 and up
Command Number	2
Command Type	Command
Command Data	New Number
Reply Data	Device Id
Persistence	Non-Volatile
Summary	Assigns new numbers to all the devices in the order in which they are connected.

If sent to device number 0, the command data is ignored and all devices will renumber. The device closest to the computer becomes device number 1. The next device becomes number 2 and so forth. If sent to a device number other than 0, then specified device will reassign itself the device number in the command data. Renumbering takes about 1/2 a second during which time the computer must not send any further data. The device number is stored in non-volatile memory so you can renumber once and not worry about issuing the renumber instruction again after each power-up.

[edit] Store Current Position - Cmd 16

Instruction Name	Store Current Position
Firmware Version	5.04 and up
Command Number	16
Command Type	Command
Command Data	Address
Reply Data	Address
Persistence	Non-Volatile
Summary	Saves the current absolute position of the device.

The device saves its current absolute position. Valid Address values are 0 through 15 specifying one of 16 possible registers in which to store the position. This command is used in conjunction with the Return Stored Position (Command #17) and Move To Stored Position (Command #18) instructions. The positions stored in the position registers are non-volatile and will persist after power-down or reset. All position registers are cleared by the Restore Settings (Command #36) instruction.

[edit] Return Stored Position - Cmd 17

Instruction Name	Return Stored Position
Firmware Version	5.04 and up
Command Number	17
Command Type	Command
Command Data	Address
Reply Data	Stored Position
Persistence	Non-Volatile
Summary	Returns the position stored in one of the 16 position registers for the device.

The device returns the position stored in one of its 16 position registers (0 thru 15) as indicated by the command data. This command is used in conjunction with the Store Current Position (#16) and Move To Stored Position (#18) commands. Positions stored in the position registers are non-volatile and will persist after power-down or reset. All position registers are cleared by the Restore Factory Settings (#36) command.

[edit] Move To Stored Position - Cmd 18

Instruction Name	Move To Stored Position
Firmware Version	5.04 and up
Command Number	18
Command Type	Command
Command Data	Address
Reply Data	Final Position
Persistence	n/a
Summary	Moves the device to the stored position specified by the Command Data.

The device moves to the position stored in the position register (0 to 15) specified by the Command Data. This command is used in conjunction with the Store Current Position (#16) and Return Stored Position (#17) commands. All move commands are pre-emptive. If a new move command is issued before the previous move command is finished, the device will immediately move to the new position. The target speed and acceleration during a move can be specified using commands 42 and 43 respectively. This command may pre-empt, or be pre-empted by commands 18, 20, 21, 22 and 23.

[edit] Move Absolute - Cmd 20

Instruction Name	Move Absolute
Firmware Version	5.00 and up
Command Number	20
Command Type	Command
Command Data	Absolute Position
Reply Data	Final position
Persistence	n/a
Summary	Moves the device to the position specified in the Command Data.

The device moves to the position specified by the command data (in microsteps). The position must be within the acceptable range for the device or an error code will be returned. All move commands are pre-emptive. If a new move command is issued before the previous move command is finished, the device will immediately move to the new position. The target speed and acceleration during a move absolute instruction can be specified using commands 42 and 43 respectively.

Command may pre-empt, or be pre-empted by commands 18, 20, 21, 22 and 23.

[edit] Move Relative - Cmd 21

Instruction Name	Move Relative
Firmware Version	5.00 and up
Command Number	21
Command Type	Command
Command Data	Relative Position
Reply Data	Final Position
Persistence	n/a
Summary	Moves the device by the positive or negative number of microsteps specified in the Command Data.

The device moves to the position given by its position before the command plus the value in command data. The final position must be within the acceptable range for the device or an error code will be returned. All move commands are pre-emptive. If a move relative command is issued while the device is currently moving due to a previous command, the device will immediately set a new target position equal to the current position (at the instant the command was received) plus the specified relative position. The target speed and acceleration during a move relative instruction can be specified using commands 42 and 43 respectively. The relative move command data (in microsteps) can be negative.

This command may pre-empt, or be pre-empted by commands 18, 20, 21, 22 and 23.

[edit] Move At Constant Speed - Cmd 22

Instruction Name	Move At Constant Speed
Firmware Version	5.00 and up
Command Number	22
Command Type	Command
Command Data	Speed
Reply Data	Speed
Persistence	n/a
Summary	Moves the device at a constant speed based on the value specified in the Command Data.

This instruction specifies a direction and a speed to move, rather than a target position. When this instruction is issued the device will accelerate (at a rate determined by command #43 Set Acceleration) to the speed specified by the instruction data. The device will continue moving at this speed until a limit is reached or a pre-empting instruction is issued. Negative speeds cause retraction while positive speeds cause extension.

To determine the actual speed that will result from a given data value, the following formulas may be used:

Actual Speed

= 9.375*(Command Data) [microsteps/sec] or

= 9.375*(Command Data)/R [steps/sec] or

= 562.5*(Command Data)/(R*S) [revolutions/min]

Where:

• Command Data is the absolute value of the Constant Speed Move instruction data
• R (microsteps/step) is the microstep resolution (command 37)
• S (steps/revolution) is the number of steps per revolution of the motor

For example, if S = 48, R = 64, and the Constant Speed Move instruction is issued with Data of 2922, then the device will move forward at a speed of approximately 535 revolutions per minute. For linear devices consult the section on Device Specific Information to determine the linear distance corresponding to a single step or revolution.

The maximum Data allowable is 512*R. Note that although the maximum data allowable depends on the resolution, the maximum speed possible is independent of the resolution. This can be seen by substituting Data = 512*R into the second formula above, giving a maximum speed (regardless of resolution) of 4800 steps/sec.

The device may be set to return its position continuously during the move using the set mode command (#40) bit 4. Position tracking is a reply-only command #8. If the device runs into zero position or maximum range, the device stops and the new position is returned via reply-only command #9.

This command may pre-empt, or be pre-empted by commands 18, 20, 21, 22 and 23.

[edit] Stop - Cmd 23

Instruction Name	Stop
Firmware Version	5.00 and up
Command Number	23
Command Type	Command
Command Data	Ignored
Reply Data	Final Position
Persistence	n/a
Summary	Stops the device from moving by preempting any move instruction.

This instruction can be used to pre-empt any move instruction. The device will decelerate (at a rate determined by command #43 Set Acceleration) and stop. The reply data is the current absolute position.

This command may pre-empt, or be pre-empted by commands 18, 20, 21, and 22.

[edit] Read Or Write Memory - Cmd 35

Instruction Name	Read Or Write Memory
Firmware Version	5.00 and up
Command Number	35
Command Type	Command
Command Data	Data
Reply Data	Data
Persistence	Non-Volatile
Summary	Reads or writes a byte of non-volatile memory.

This command is used to read or write a byte of non-volatile memory. 128 bytes of memory are available for user data. For example, the user may want to save some custom data such as a serial number, a name string, or data that uniquely identifies a particular device. Data written is not cleared by power down or reset. The most significant bit of byte 3 specifies whether the instruction is a read (0) or a write (1). The least significant 7 bits of byte 3 specify the address to read/write (0 to 127). Byte 4 specifies the value to be written. Bytes 5 and 6 are ignored.

These settings are stored in non-volatile memory and will persist after power-down or reset.

[edit] Restore Settings - Cmd 36

Instruction Name	Restore Settings
Firmware Version	5.00 and up
Command Number	36
Command Type	Command
Command Data	Peripheral Id
Reply Data	Peripheral Id
Persistence	Non-Volatile
Summary	Restores the device settings to the factory defaults.

This command should be issued with a Peripheral Id of 0 to return the device to factory default settings. This instruction is very useful for troubleshooting. If the device does not appear to function properly, it may be because some of the settings have been changed. This instruction will restore the settings to default values. For a table of default settings, see Appendix A. All settings affected by this instruction are stored in non-volatile memory and will persist after power-down or reset.

[edit] Set Microstep Resolution - Cmd 37

Instruction Name	Set Microstep Resolution
Firmware Version	5.00 and up
Command Number	37
Command Type	Setting
Command Data	Microsteps
Reply Data	Microsteps
Persistence	Non-Volatile
Summary	Changes the number of microsteps per step.

This setting changes the number of microsteps per step. Valid data are 1, 2, 4, 8, 16, 32, 64, and 128. The default on most devices is 64. All position data sent to or received from T-Series products is in units of microsteps. Note that when you change the microstep resolution using this command, other position related settings are changed automatically to adjust for the new microstep size. The table below gives an example showing how other settings are affected when the microstep resolution is changed from 128 to 64:

Setting	Before	After
Target Speed *	2922	1461
Maximum Travel Range *	280000	140000
Current Position	10501 **	5250 **
Maximum Relative Move *	20000	10000
Home Offset *	1000	500
Acceleration *	100	50

* The setting for these command is saved in non-volatile memory, i.e. the setting persists even if the device is powered down. To restore all non-volatile settings to factory default, use command 36.

** Note that if a number is divided by two, it is rounded down to the nearest whole number. The only exception to this is if acceleration would become 0 (because 0 for acceleration indicates infinite acceleration). If acceleration would become 0, it will instead be set to 1 which is the lowest acceleration possible.

[edit] Set Running Current - Cmd 38

Instruction Name	Set Running Current
Firmware Version	5.00 and up
Command Number	38
Command Type	Setting
Command Data	Value
Reply Data	Value
Persistence	Non-Volatile
Summary	Places a current limit on the device. RunningCurrent = CurrentCapacity*10/CommandData)

The current is related to the data by the formula:

RunningCurrent = CurrentCapacity*10/CommandData)

The Command Data can be either 0 (no current) or 10 (maximum current) through 127 (minimum current). Note that values of 1 through 9 are not accepted. CurrentCapacity is the hardware’s maximum capability of output current. In other words, as a fraction of the maximum current the device is capable of, the running current will be 10/CommandData.

[edit] Special Note

Most devices limit the voltage rather than the current. In this case you can think of the CurrentCapacity as the power supply voltage and the RunningCurrent as the effective voltage being applied to the motor. For example, if a product uses a 5V motor and has a 15V power supply, the running current might be set as follows:

Command Data = 10 * CurrentCapacity / RunningCurrent
             = 10 * 15V / 5V
             = 30

If your application does not require high torque, it is best to decrease the RunningCurrent to reduce power consumption, vibration, and motor heating. Trial and error should suggest an appropriate setting. If higher torque is required, it is generally safe to overdrive motors as long as they are not operated continuously. Motor temperature is typically the best indication of the degree to which overdriving can be employed. If the motor gets too hot to touch (>75°C), you should reduce the running current.

[edit] Set Hold Current - Cmd 39

Instruction Name	Set Hold Current
Firmware Version	5.00 and up
Command Number	39
Command Type	Setting
Command Data	Value
Reply Data	Value
Persistence	Non-Volatile
Summary	Sets the desired current to be used when the device is holding its position. HoldCurrent = CurrentCapacity * 10 / CommandData.

The formula for the hold current works the same way as for running current. It is typical to run stepper motors at their rated current only during moves (for highest torque) and reduce the current when idle just to hold the position.

The range of accepted values is 10 - 127 (and 0). Typically the hold current can be set to around 25 - 50% of the running current. If the running current is set to a value of 24, the hold current may be set to a value of 48 to provide 50% hold. In some applications, the friction of the drive system alone is sufficient to hold the microstep position of the motor, and the hold current can be turned off completely. The hold current can be turned off by issuing the "Set Hold Current" instruction with data of 0.

When the device is moving, it applies running current to the motor. When the device stops moving, running current is applied for an additional 0.1 second before hold current is applied.

[edit] Set Device Mode - Cmd 40

Instruction Name	Set Device Mode
Firmware Version	5.04 and up
Command Number	40
Command Type	Setting
Command Data	Mode
Reply Data	Mode
Persistence	Non-Volatile
Summary	Sets the Mode for the given device.

[edit] Special Note

This command allows setting several options. Each option is controlled by a single bit within the command data. Most software you will encounter, including most of our demo software, represents all 4 data bytes as a single decimal value rather than specifying each bit individually. To determine what decimal value to use requires a basic understanding of how the data is represented in binary. The command data may be considered as a single 32-bit binary value. The least significant bit is bit_0, the next is bit_1, the next is bit_2, and so on up to the most significant bit_31. Each bit may have a value of either 1 or 0.

The corresponding decimal representation of this 32-bit data is given by:

Decimal value  = (bit_0 * 1) + (bit_1 * 2) + … + (bit_n * 2^n) + … + (bit_31 * 2^31)

Each bit controls a single mode option as described in the table below. To determine the data value to use with the Set Device Mode command, simply determine the desired value of each bit (1 or 0), and calculate the decimal value using the above formula. Note that not all 32 bits are currently used. Any unused or reserved bits should be left as 0.

For example, suppose you want all mode bits to be 0 except for bit_3 (disable potentiometer), bit_14 (disable power LED), and bit_15 (disable serial LED). The Set Device Mode instruction should be sent with data calculated as follows:

Command Data  = 2^23 + 2^214 + 2^215
              = 8 + 16384 + 32768
              = 49160

Note that each instance of the Set Device Mode command overwrites ALL previous mode bits. Repeated commands do not have a cumulative effect. For example, suppose you send a Set Device Mode command with data of 8 to disable the potentiometer. If you then send another Set Device Mode command with data of 16384 to disable the power LED, you will re-enabled the potentiometer since bit_3 in the 2nd instruction is 0.

Most devices have a default mode setting of 0 (all bits are 0), however, there are some exceptions. See T-Series/Device Ids and Default Settings for a table of default settings for all devices.

*Anti-backlash and Anti-sticktion routines are designed to compensate for backlash and sticktion. The solution to backlash is to always approach a position from the same direction. The solution to sticktion is to move the device far enough away from the final position to break free of sticktion before attempting the final move. The operation of the two features are dependent on each other, and the interaction of enabling one or both of the features is described in the diagram to the right.

For each setting scenario, the starting position is denoted by the solid vertical line and the final position is denoted by the dotted vertical line. There are four possible moves for each scenario: long move positive, long move negative, short move positive and short move negative. The arrows show the path that would be traversed for each scenario.

[edit] Set Target Speed - Cmd 42

Instruction Name	Set Target Speed
Firmware Version	5.00 and up
Command Number	42
Command Type	Setting
Command Data	Speed
Reply Data	Speed
Persistence	Non-Volatile
Summary	Sets the speed at which the device moves when using the "Move Absolute" or "Move Relative" commands.

When a move absolute or move relative instruction is issued, the device will accelerate at a rate determined by the acceleration setting up to a maximum speed determined by this command, “Set Target Speed". To determine the actual speed that will result from a given data value, the following formulas may be used:

Actual Speed = 9.375*Data [microsteps/sec] or  
             = 9.375*Data/R [steps/sec] or           
             = 562.5*Data/(R x S) [revolutions/min]             

Where:

• "Command Data" is the absolute value of the Constant Speed Move Command Data
• R (microsteps/step) is the microstep resolution (command 37)
• S (steps/revolution) is the number of steps per revolution of the motor

For example, if S = 48, R = 64, and the Constant Speed Move instruction is issued with Data of 2922, then the device will move forward at a speed of approximately 535 revolutions per minute. For linear devices consult the section on Device Specific Information to determine the linear distance corresponding to a single step or revolution.

The maximum Data allowable is 512*R. Note that although the maximum data allowable depends on the resolution, the maximum speed possible is independent of the resolution. This can be seen by substituting Data = 512*R into the second formula above, giving a maximum speed (regardless of resolution) of 4800 steps/sec.

The target velocity may be changed on-the-fly even when the device is in the middle of a move. The device will automatically adjust the velocity, but still target the final position specified in the original move.

[edit] Set Acceleration - Cmd 43

Instruction Name	Set Acceleration
Firmware Version	5.00 and up
Command Number	43
Command Type	Setting
Command Data	Acceleration
Reply Data	Acceleration
Persistence	Non-Volatile
Summary	Sets the acceleration used by the "Absolute Move" and "Relative Move" commands.

When a move absolute or move relative instruction is issued, the device will accelerate at a rate determined by this command “Set Acceleration” up to a maximum speed determined by the target velocity. To determine the acceleration that will result from a given data value, the following formulas may be used:

Actual Acceleration   =  11250*(Command Data)   [microsteps/sec^2]  
                      =  11250*(CommandData/R)  [steps/sec^2]

Where:

• "Command Data" is the value specified in the Command Data by the user
• R is the microstep resolution set in command #37(microsteps/step)

The maximum value allowable is 512*R. This is the same as the maximum allowable data for velocity, which means that the device will reach maximum velocity immediately. If acceleration is set to 0, it is as if acceleration is set to 512*R. Effectively acceleration is turned off and the device will start moving at the target speed immediately.

The acceleration may be changed on-the-fly even when the device is in the middle of a move. The device will still target the final position specified in the original move.

[edit] Set Maximum Range - Cmd 44

Instruction Name	Set Maximum Range
Firmware Version	5.00 and up
Command Number	44
Command Type	Setting
Command Data	Range
Reply Data	Range
Persistence	Non-Volatile
Summary	Sets a limit on the range of travel up to 16777216.

Use this command to limit the range of travel to a value other than the default. Exercise caution since using this command it is possible to set the range to a value greater than the physical limits of the device. The maximum range you can set is 16777216 microsteps.

This setting is stored in non-volatile memory and will persist after power-down or reset.

[edit] Set Current Position - Cmd 45

Instruction Name	Set Current Position
Firmware Version	5.00 and up
Command Number	45
Command Type	Setting
Command Data	New Position
Reply Data	New Position
Persistence	Volatile
Summary	Sets the the internal register that holds the position to the value specified in the command data.

The internal register that holds the position is set to the value given by the command data. The phase of the stepper motor is controlled by the least significant byte of the position, thus the device may move by +/- 2 full steps unless the new position corresponds to the true current position of the device. This command is useful if you want to turn off the system without losing position. Simply save the position in the controlling computer before powering down. After powering up, set the position back to the saved value. In this way you can continue without having to home the device.

The position data is volatile and will not persist after power-down or reset.

[edit] Set Maximum Relative Move - Cmd 46

Instruction Name	Set Maximum Relative Move
Firmware Version	5.00 and up
Command Number	46
Command Type	Setting
Command Data	Range
Reply Data	Range
Persistence	Non-volatile
Summary	Sets a limit on the number of microsteps the device can make for a Relative Move command.

Use this command to limit the maximum range of travel for a relative move command. For example, if maximum relative move is set to 1000, and the user requests a relative move (#21) of 800, then the device will move 800 microsteps. However, if the user requests a relative move of 1200, then the device will reply with an error code. Most applications can leave this unchanged from the default.

This setting is stored in non-volatile memory and will persist after power-down or reset.

[edit] Set Home Offset - Cmd 47

Instruction Name	Set Home Offset
Firmware Version	5.00 and up
Command Number	47
Command Type	Setting
Command Data	Offset
Reply Data	Offset
Persistence	Non-Volatile
Summary	Sets the the new "Home" position which can then be used when the Home command is issued.

When the home command is issued, the device will retract until the home sensor is triggered, then move forward until the home sensor is no longer triggered, then move forward by the Home Offset value (in microsteps) and call this position 0.

Note that the home offset command also changes the range. For example, if the initial home offset is 0 and the range is 500,000, and the user changes the home offset to 70,000, then the range is automatically adjusted to be 430,000. However, changing the range does not affect the home offset.

This setting is stored in non-volatile memory and will persist after power-down or reset.

[edit] Set Alias Number - Cmd 48

Instruction Name	Set Alias Number
Firmware Version	5.00 and up
Command Number	48
Command Type	Setting
Command Data	Alias Number
Reply Data	Alias Number
Persistence	Non-Volatile
Summary	Sets an alternate device number for a device.

This setting specifies an alternate device number for a device (in addition to its actual device number). By setting several devices to the same alias number, you can control groups of devices with a single instruction. When you send an instruction to an alias number, all devices with that alias number will execute the instruction and reply using their actual device numbers. To remove an alias, simply set the devices alias number to zero. Valid alias numbers are between 0 and 254. To avoid confusion, it is best to choose an alias greater than the number of devices connected.

This setting is stored in non-volatile memory and will persist after power-down or reset.

[edit] Lock Settings - Cmd 49

Instruction Name	Lock Settings
Firmware Version	5.07 and up
Command Number	49
Command Type	Command
Command Data	Lock Status
Reply Data	Lock Status
Persistence	Non-Volatile
Summary	Locks or unlocks all non-volatile settings.

Sometimes it is desirable to lock all non-volatile settings to prevent them from being changed inadvertently. After changing all settings as desired, settings can be locked by sending this instruction with a Lock Status of 1. Subsequent attempts to change any non-volatile setting (ex. changing the speed, command 42) will result in an Error Response with an error code of 3600 (settings locked).

How the Restore Settings instruction behaves when the settings are locked depends on the firmware version. In version 5.07 issuing a Restore Settings instruction while the settings are locked will result in an Error Response with an error code of 3600 (settings locked). This behavior was found to confuse many customers so in version 5.08 and up, the behavior was changed such that regardless of the current lock status, issuing a Restore Settings instruction will always return setting values to factory default values and leave settings in an unlocked state.

Settings can also be unlocked by sending the Lock instruction with a Lock Status of 0.

[edit] Return Device Id - Cmd 50

Instruction Name	Return Device Id
Firmware Version	5.00 and up
Command Number	50
Command Type	Read-Only Setting
Command Data	Ignored
Reply Data	Device Id
Persistence	n/a
Summary	Returns the Id code for the type of device connected.

This causes the device to return an identification code indicating the type of device connected. See http://www.zaber.com/wiki/T-Series/Device_Ids for a table of device Ids for all Zaber products.

[edit] Return Firmware Version - Cmd 51

Instruction Name	Return Firmware Version
Firmware Version	5.00 and up
Command Number	51
Command Type	Read-Only Setting
Command Data	Ignored
Reply Data	Version
Persistence	n/a
Summary	Returns the firmware version installed on the device.

This setting indicates the firmware version installed on the device. A decimal is assumed before the last two digits. For example, 502 indicates firmware version 5.02.

[edit] Return Power Supply Voltage - Cmd 52

Instruction Name	Return Power Supply Voltage
Firmware Version	5.00 and up
Command Number	52
Command Type	Read-Only Setting
Command Data	Ignored
Reply Data	Voltage
Persistence	n/a
Summary	Returns the voltage level of the device's power supply.

This setting indicates the voltage level of the device's power source. A decimal is assumed before the last digit. For example, a value of 127 indicates 12.7 V. Note that the internal voltage measurement is not very accurate. Don't be alarmed if the indicated voltage is slightly different from your measurements.

[edit] Return Setting - Cmd 53

Instruction Name	Return Setting
Firmware Version	5.00 and up
Command Number	53
Command Type	Command
Command Data	Setting Number
Reply Data	Setting Value
Persistence	n/a
Summary	Returns the current value of the setting specified in the Command Data.

This causes the device to return the current value of the setting number specified in the command data. Valid setting numbers are the command numbers of any "Set..." instruction. The device will reply using the command number of the specified setting (as if a command to change the setting had just been issued) but the setting will not be changed.

For example, command #43 is the "Set Acceleration" instruction. Therefore if you wish to return the current value of the acceleration setting, simply send the Return Setting instruction with data of 43. The device will reply with command #43 and data equal to the setting value.

[edit] Return Status - Cmd 54

Instruction Name	Return Status
Firmware Version	5.00 and up
Command Number	54
Command Type	Read-Only Setting
Command Data	Ignored
Reply Data	Status
Persistence	n/a
Summary	Returns the current status of the device.

This read-only setting specifies the current status of the device. Status codes are as follows:

• 0 - idle, not currently executing any instructions
• 1 - executing a home instruction
• 10 - executing a manual move (i.e. the manual control knob is turned)
• 20 - executing a move absolute instruction
• 21 - executing a move relative instruction
• 22 - executing a move at constant speed instruction
• 23 - executing a stop instruction (i.e. decelerating)

[edit] Echo Data - Cmd 55

Instruction Name	Echo Data
Firmware Version	5.04 and up
Command Number	55
Command Type	Command
Command Data	Data
Reply Data	Data
Persistence	n/a
Summary	Echos back the same Command Data that was sent.

This causes the device to echo back the same Command Data that was sent.

[edit] Return Current Position - Cmd 60

Instruction Name	Return Current Position
Firmware Version	5.00 and up
Command Number	60
Command Type	Read-Only Setting
Command Data	Ignored
Reply Data	Position
Persistence	n/a
Summary	Returns the current absolute position of the device.

This causes the device to return its current absolute position in microsteps.

[edit] Error - Cmd 255

Instruction Name	Error
Firmware Version	5.00 and up
Command Number	255
Command Type	Reply
Command Data	n/a
Reply Data	Error Code
Persistence	n/a
Summary	Indicates to the user that an error has occurred.

This reply indicates that an error has occurred. The error code returned in the data indicates the type of error. The device may send an error code as a reply to an invalid instruction, or it may autonomously send an error code as a triggered reply (i.e. not in response to an instruction). The error code is typically the command number of the instruction that caused the error, but not always.

[edit] Error Codes

[edit] Reply-Only Reference

In general, a T-series device will reply to an instruction using the same command number as the instruction itself. However, there are occasions (such as when the user turns the potentiometer) when the device may transmit data without first receiving a request from the controlling computer. This type of reply may be considered to be a triggered reply as opposed to a requested reply. In this case the device uses a “reply-only” command number to distinguish the reply from those requested by the controlling computer. The meanings of these replies and their corresponding data are given below.

[edit] Constant Speed Tracking - Cmd 8

Instruction Name	Constant Speed Tracking
Firmware Version	5.00 and up
Command Number	8
Command Type	Reply
Command Data	n/a
Reply Data	Tracking Position
Persistence	n/a
Summary	Indicates to the user that the device has been set to a position tracking mode and given a move instruction.

The device has been set to position tracking mode (see Set Mode instruction) and given a move instruction. In this mode, the device sends this reply every 0.25 seconds updating the current absolute position (in microsteps) during any move.

[edit] Limit Active - Cmd 9

Instruction Name	Limit Active
Firmware Version	5.00 and up
Command Number	9
Command Type	Reply
Command Data	n/a
Reply Data	Final Position
Persistence	n/a
Summary	Indicates to the user that the device has reached one of the limits of travel.

This response from a device indicates that it reached one of the limits of travel (either the minimum position or maximum position). For example, if a device is sent a “move at constant speed” instruction, and it reaches the maximum range of travel then the device will reply with this command number and the maximum position reached as data.

[edit] Manual Move Tracking - Cmd 10

Instruction Name	Manual Move Tracking
Firmware Version	5.00 and up
Command Number	10
Command Type	Reply
Command Data	n/a
Reply Data	Tracking position
Persistence	n/a
Summary	A reply that is sent when the manual control knob is turned.

The device has been moved manually (the knob is turned). If enabled with the Set Mode instruction, the device sends this reply at regular intervals updating the current position during manual moves.

[edit] Manual Control

Turning the potentiometer knob will make the device move. It is not necessary to have a computer connected to use the device in manual mode. However, without a computer connected you have no means to initialize the device with a starting position. Therefore you must retract it completely after each power up in order to home the device. You will not be able to extend it fully until you have first retracted it completely to set the home position. Clockwise rotation of the knob produces positive motion (extension) and counter clockwise rotation produces negative motion (retraction).

The speed of retraction or extension will be directly related to the amount to which the knob is turned from its center detent position (turning the knob to its center position will stop the device from moving). During manual moves, the device constantly returns its position so a computer can track the position even when you are controlling the device manually. Manual control can be disabled with a mode setting.

The speed of the potentiometer-controlled manual moves is also determined by the Set Target Velocity command (#42). When the knob is fully turned to either limit, the device will move at the maximum velocity set by command #42. Any intermediate position of the knob will move the device at a velocity proportional to how far the knob has been turned. If the velocity is set to be very small, it may appear that turning the knob produces no movement. The way to verify that the actuator is moving is to connect it to a computer and monitor the replies back to the computer.

During operation if the actuator is extended or retracted against a force greater than its thrust capability the device will stall and there will be “missed steps”. This can result in an apparent malfunction in that the device believes its position to be other than it actually is and will not extend or retract the actuator past a given position. Without connecting a computer to home the device or set its position, the only solution is to retract the actuator until it activates the internal home switch, which will automatically zero the device at the home position. A problem arises if the device incorrectly believes its position to be zero since it will not retract to the home position. In this case you must disconnect and reconnect the power before manually homing the device.

[edit] LED functions

The green LED is on whenever there is power to the device. A constant blinking (2Hz) of the green LED indicates that the power supply is out of range. The green LED may be disabled by a mode bit (see command #40)

The amber LED flashes when there is traffic packet on the RS232 line. It also stays constantly on while the device is moving. When the potentiometer is turned, the amber LED will blink at a rate that is proportional to how far the potentiometer is turned. The further the knob is turned away from center detent, the faster the amber LED will blink. If the device reaches either the home or the away limit while under manual move, the amber LED will blink slower (2Hz) to indicate that the device cannot move any further.

[edit] Troubleshooting Motion Devices

[edit] Warranty and Repair

All Zaber products are backed by a one-month satisfaction guarantee. If for any reason you are not satisfied with your purchase, send it back to Zaber Technologies Inc. within one month of the purchase date for a refund. A restocking fee of the greater of $100 or 5% will be applied to cover administration and customs fees charged to us. Goods must be in brand new condition with no marks. T-series devices are also guaranteed for one year or 50,000 cycles, whichever comes first. During this period Zaber will repair or replace faulty units free of charge. Customers with devices in need of repair should contact Zaber to obtain an RMA form which must be filled out and returned to receive an RMA number. The RMA form also contains instructions for packing and returning the device.

[edit] Email Updates

If you would like to receive our email newsletter including product updates and promotions, please sign up online at http://www.zaber.com (news section). Each newsletter typically includes a promotional offer worth at least $100. We do not send more than 4 newsletters per year.

[edit] Contact Information

Contact Zaber Technologies Inc by any of the following methods:

Phone	1-604-276-8033 (direct) 1-888-276-8033 (toll free in North America)
Fax	1-604-648-8033
Mail	2891 Steveston Hwy, Richmond, BC, Canada, V7E 2J1
Web	http://www.zaber.com
Email	Please visit our website for up to date email contact information.

[edit] Appendix A: Default Settings

Setting	Cmd#	T- LS13-I LS13-M LS13-SI LS13-SM	T- LS13B-I LS13B-M LS13B-SI LS13B-SM	T- LS28-I LS28-M LS28-SI LS28-SM	T- LS28B-I LS28B-M LS28B-SI LS28B-SM	T- LS80-I LS80-M LS80-SI LS80-SM	T- LS80B-I LS80B-M LS80B-SI LS80B-SM
Device Id	na*	113	1113	128	1128	180	1180
Microstep Resolution	37	64	128	64	128	64	128
Running Current	38	10	17	10	17	10	17
Hold Current	39	0	50	50	50	0	50