SMAC LAC-25 Technical Reference Manual

SMAC

LAC-25

TECHNICAL REFERENCE MANUAL

Revision 3.4, February 1998

SMAC CORP.

5807 Van Allen Way

Carlsbad, CA 92008

S.M.A.C.

5807 VAN ALLEN WAY

CARLSBAD, CA 92008

PHONE: [phone] / FAX: [phone]

FOR TECHNICAL ASSISTANCE CALL: 1-760-929-7575

© COPYRIGHT A UTOMATION MODULES , INC. 1993 - 1998

SMAC LAC-25 Technical Reference Manual

Table of Contents

1. INTRODUCTION ............................................................................................................................7

1.1 SPECIFICATIONS .............................................................................................................................7

1.2 DIGITAL I/O INTERFACE....................................................................................................................8

1.2.1 Dedicated Digital Inputs .......................................................................................................8

1.2.2 General Purpose Inputs.........................................................................................................8

1.2.3 General Purpose Outputs......................................................................................................9

1.2.4 Digital I/O "States"................................................................................................................9

1.2.5 I/O Technical Specifications..............................................................................................10

1.3 ENCODER INTERFACE....................................................................................................................11

1.4 OUTPUT DRIVER INTERFACE ...........................................................................................................11

1.5 ANALOG TO DIGITAL CONVERSION (A/D) INTERFACE............................................................................11

1.6 SERIAL INTERFACE ........................................................................................................................11

2. MACRO INTERRUPT SYSTEM ....................................................................................................13

2.1 THE INTERRUPT VECTOR TABLE......................................................................................................13

2.2 ENABLING AND DISABLING INTERRUPTS .............................................................................................13

2.3 INTERRUPT SOURCES....................................................................................................................14

2.4 INTERRUPT PRIORITY ....................................................................................................................14

2.5 INTERRUPT COMPLETION................................................................................................................15

2.6 INTERRUPT LATENCY.....................................................................................................................15

3. ENTERING COMMANDS..............................................................................................................17

3.1 DOWNLOADING COMMANDS ............................................................................................................18

4. INTRODUCTION TO COMMANDS................................................................................................19

4.1 PARAMETER COMMANDS................................................................................................................19

4.2 REPORTING COMMANDS.................................................................................................................30

4.3 MOTION COMMANDS .....................................................................................................................37

4.4 REGISTER COMMANDS...................................................................................................................44

4.4.1 Internal Variables................................................................................................................44

4.5 SEQUENCE COMMANDS .................................................................................................................52

4.6 LEARNED POSITION STORAGE (LPS) COMMANDS ..............................................................................57

4.7 MACRO COMMANDS ......................................................................................................................58

4.8 INPUT / OUTPUT (I/O) COMMANDS ..................................................................................................62

4.9 FUTURE EXPANSION INTERFACE ......................................................................................................64

4.10 SERIAL COMMUNICATIONS AND MISCELLANEOUS COMMANDS .............................................................65

5. APPENDIX A, LAC-25 ERROR CODE DEFINITIONS ...................................................................72

6. APPENDIX B, SUMMARY OF LAC-25 COMMANDS.....................................................................74

7. APPENDIX C, LAC-25 CONNECTOR PIN DEFINITIONS..............................................................75

8. INDEX .........................................................................................................................................76

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SMAC LAC-25 Technical Reference Manual

1. Introduction

The LAC-25 is a two axis stand-alone integrated controller / driver, with input / output (I/O)
capabilities, designed primarily for the control of DC brush type motors or actuators with itÕs
integrated driver, or other types or motors by interfacing the onboard analog output capabilities
with external drivers.

The LAC-25 implements a mnemonic type command instruction set via a standard RS-232
serial communications interface. These commands can be executed directly or used to create
command macros which are stored in the onboard nonvolatile RAM (NVRAM).

The LAC-25 can interface to the real world via the onboard motor drivers, 2 channels of
quadrature type encoder interface, 4 channels of optoisolated digital input and 4 channels of
optoisolated digital output, with additional optoisolated inputs serving for limit, home and fault
functions, 5 channels of 10-bit analog to digital (A/D) conversion (2 of which are reserved for
monitoring amplifier output current), and an RS-232 serial communications link. A proprietary RS­422 interface is provided for future I/O expansion modules.

1.1 Specifications

Description Stand-Alone 2 Axis Servo Motor Controller / Driver
Operating Modes Position, Velocity, Torque and Electronic Gearing
Filter Algorithm PID
Max. Filter Update Rate 100 µS Per Enabled Axis
Trajectory Generator Trapezoidal, Electronic Gearing
Servo Position Feedback Incremental Encoder with Index
Output (Standard) PWM Motor Drive, 3 Amps Cont. and 6 Amps Peak at 50 VDC

Max.
PWM Frequency Approximately 19.531 KHz
Encoder And Index Input Single-ended or Differential
Encoder Supply Voltage 5 VDC
Encoder Input Voltage 5.5 VDC Max., -0.1 VDC Min.
Encoder Count Rate 2 Million Quadrature Counts per Second
Position Range 32 Bits
Velocity Range 31 Bits
Acceleration Range 31 Bits
General Purpose Digital

I/O
Dedicated Digital Inputs Limit+, Limit-, Home and Fault for each axis
Analog Inputs 5 Channels With 10-Bit Resolution, 3 are user accessible

Analog Outputs 2 Channels With 12-Bit Resolution, ±10VDC.

Communication Interface RS-232 Serial Interface, Adjustable Baud Rate, 8 Bits, 1 Stop Bit,

Supply Voltage +18 To +50 VDC
Motor Voltage +12 To +48 VDC
Dimensions Approximately 7.6Ó Long by 3.3Ó Wide by 1.1Ó Thick
Weight Approximately 1 Lb.

4 Optoisolated Inputs, 4 Optoisolated Outputs

No Parity, XON/XOFF Handshake

Table 1. Specifications.

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1.2 Digital I/O Interface

The LAC-25 includes 4 channels of general purpose digital input and 4 channels of
general purpose digital output. Additionally, there are four channels of dedicated digital input for
each of the two axis'. All of these I/O are protected through the use of optoisolators.

1.2.1 Dedicated Digital Inputs

Figure 1 illustrates one of the LAC-25Õs dedicated digital inputs. These inputs are Limit+,
Limit-, Home and Fault for both axis of the LAC-25. The power to activate these inputs is provided
by the LAC-25 so it is only necessary to complete the circuit to activate the input.

The Limit inputs are intended for signaling the LAC-25 that an axis has reached itÕs end of
travel. When such an event occurs, the LAC-25 can ignore the event or stop the servo in some
controlled fashion. The Home input is for detecting some sort of "home position" sensor. This c an
be used with the encoder index input to implement a very accurate homing method. A typical use
for the Fault input is for an external device to signal a fault condition such as over-temperature.

Note: The external Fault input is tied to the internal over-temperature signal from the onboard

drivers. When a fault condition occurs, that is either the internal over-temperature signal or
external Fault signal go active, the 16-bit internal variable FCNT (see Internal Variables)
begins to increment at 1 rate of once per millisecond. If the fault condition clears then the
FCNT variable is also cleared. If the fault condition remains present long enough for the
FCNT variable to count up to the value assigned to the FCMP variable, then the over Fault
bit in the status word will be set and the servo will be disabled (assuming the Fault interrupt
has not been enabled). The default value for FCMP is 10000 which will give a 10 second
delay before causing the Fault bit to be set.

1.2.2 General Purpose Inputs

Figure 2 illustrates one of the LAC-25Õs general purpose inputs. These inputs are
galvanically isolated from the LAC-25. Current of the proper polarity must be supplied to the circuit
to activate the input.

Figure 1. LAC-25 Dedicated Input.

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Figure 2. LAC-25 General Purpose Inputs

1.2.3 General Purpose Outputs

Figure 3 illustrates one of the LAC-25Õs general purpose outputs. These outputs are
galvanically isolated from the LAC-25. When an output is activated, positive current will flow from
the collector of the optocoupler transistor (the output pin) to itÕs emitter (the output return pin),

Figure 3. LAC-25 General Purpose Output

1.2.4 Digital I/O "States"

There are several commands that deal with controlling the digital I/O. All of these
commands operate based on the following philosophy: With regard to an input, "active" means
there is sufficient current flowing through that input and "inactive" means there is lack of sufficient
current through that input. With regard to outputs, "active" means the ability for an output to pass
current and "inactive" means the inability for an output to pass current.

The Channel High (CH) and Channel Low (CL) commands provide the user with the ability
to determine whether a channel is active in the "on" state (CH) or active in the "off" state (CL). This
is analogous to a switch and to whether it is normally open or normally closed. The Channel On
(CN) and Channel Off (CF) commands do exactly as they imply in that they will turn a given output
either on or off, which will make that output either active or inactive depending on the CH and CL
commands as stated previously.

The (CH) command causes the following interpretation of the inputs and outputs:

• An "activated" output is considered to be ON (e.g., Channel On ÒCNÓ command).

• An "inactivated" output is considered to be OFF (e.g., Channel Off ÒCFÓ command).

• An "activated" input is considered to be ON (e.g., Do If On ÒDNÓ command).

• An "inactivated" input is considered to be OFF (e.g., Do If Off ÒDFÓ command).

The (CL) command causes the following interpretation of the inputs and outputs:

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SMAC LAC-25 Technical Reference Manual

• An "activated" output is considered to be OFF (e.g., Channel Off ÒCFÓ command).

• An "inactivated" output is considered to be ON (e.g., Channel On ÒCNÓ command).

• An "activated" input is considered to be OFF (e.g., Do If Off ÒDFÓ command).

• An "inactivated" input is considered to be ON (e.g., Do If On ÒDNÓ command).

Input Current ÒCHÓ ÒCLÓ Output Current ÒCHÓ ÒCLÓ

Flowing On Off Flowing CN CF

No Flow Off On No Flow CF CN

Table 2. I/O States.

Another feature of the digital input system is the ability for software input debouncing. All of
the general purpose digital inputs are automatically sampled once every millisecond. Depending
on the debounce delay set by the Input Debounce (ID) command, a given input must remain in the
same state during one or more samplings before it is considered valid. If an input were to be found
in a changed state during a sampling, the input would become invalid and the debounce delay
would be restarted. If no or "0" debounce delay is used, then no input debouncing is performed. For
example: if a "ID5" command has been issued, then a given input must remain in the same state
for 5 samplings or for 5 milliseconds.

1.2.5 I/O Technical Specifications

1.2.5.1 General Purpose I/O Nominal Specifications.

Unit Specification

5 V Minimum voltage to activate input.

0.83 mA Input current at minimum activation voltage.
24 V Maximum input voltage.

4.87 mA Input current at maximum voltage.

1.1 V Maximum voltage to deactivate input.
6 V Absolute maximum reverse input voltage.

40 V Maximum voltage output can sustain.

100 mA Maximum current output can sustain.

Table 3: General Purpose I/O Specifications

1.2.5.2 Dedicated I/O Nominal Specifications.

Unit Specification

10 Ω Maximum external circuit resistance to activate

input.

1K Ω Minimum external circuit resistance to deactivate

input.

Table 4: Dedicated I/O Specifications

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SMAC LAC-25 Technical Reference Manual

1.3 Encoder Interface

The LAC-25 has two channels of quadrature type encoder interface with optional index
signal input and the ability to supply +5 VDC at a minimum of 50 mA (or greater depending on
other demands put on the internal 5 VDC power supply). The phase A+ and phase B+ inputs are
pulled up to +5 VDC with 2.7K resistors, and the phase A- and phase B- inputs a biased at +2.5 VDC
with 2.7K resistors. This arrangement which will accommodate both open collector and totem pole
single-ended output encoders or differential output encoders. The phasing of the channels as well
as the index signal sense can be changed via program command.

1.4 Output Driver Interface

The LAC-25 onboard output drivers are PWM switching amplifiers capable of supplying 3
Amps continuous and 6 Amps peak (for 200 mS minimum) at a switching frequency of
approximately 19.531 KHz. These drivers are intended for driving DC brush type motors or
actuators. Both drivers share the main power supply input and the peak voltage output to the motor
will be nearly that of what is supplied.

The output drivers include an over-temperature sensor. If this sensor determines that the
amplifierÕs temperature is greater than 140¡ C, the amplifier will then be disabled and the Over­Temperature bit will be set in that axis' status word.

For applications requiring capabilities above those of the onboard drivers, the ability to

interface to external drivers is provided. This consists a 12-bit D/A ±10 VDC analog output signal for

each axis. In applications where external drivers are not required, the analog outputs can be used
for other purposes (e.g.,: oscilloscope monitoring of following error or output command).

1.5 Analog to Digital Conversion (A/D) Interface

The LAC-25 provides a 5 channel, 10 bit A/D conversion interface with a +10 VDC
reference and analog ground. For reverse compatibility purposes the A/D interface is actually

ten channels but the user is only given access to channels 0, 1 and 2 while channels 6 and 7
are used internally for monitoring the output current of the onboard drivers. The other channels
are unavailable and should be ignored.

Whenever a Tell Analog "TA" or Get Analog "GA" command is issued, the specified A/D
channel is converted and the result is either reported or stored for access by the user. Also,
whenever the servo loop for an axis is executed, the "current monitoring" channel for that axis is
converted and the result is stored for later access.

1.6 Serial Interface

The LAC-25 communicates with a host computer or a "dumb" terminal via an RS-232 serial
interface. The baud rate is user selectable from 300 to 19,200 baud with 9600 baud being the
default. Characters are fixed at 8 bits in length with 1 stop bit and no parity. Software XON / XOFF
handshaking is provided. Hardware handshaking is not supported at this time.

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SMAC LAC-25 Technical Reference Manual

2. Macro Interrupt System

The LAC-25 employs a "Macro Interrupt System" to provide additional versatility i n
programming the LAC-25. This system comprises 32 interrupt sources with corresponding vectors.
When an interrupt's source is enabled for operation and then becomes active, the current macro
being executed is saved to a so called macro stack and execution of the macro specified by that
interrupt's vector table entry begins. This happens to be similar procedure to that which the Macro
Call (MC) command follows.

2.1 The Interrupt Vector Table

The Interrupt Vector Table consists of an entry for each interrupt source and each entry will
correspond to that interrupt's level (level 0 = entry 0, level 1 = entry 1, etc.). A particular table entry
must be loaded with the number of a valid macro to be executed should that interrupt source
become active. The method for loading a vector table entry is provided by the Load Vector (LV)
command. The user must first use the Accumulator Load (AL) command to set the number of the
macro for a vector. The LV command is then used to transfer the low 8-bits of the accumulator to
the vector table entry specified by the LV command. If an interrupt is generated and that vector
table entry has not been defined (equal to 0) then the interrupt will not be executed. Note that this
implies that macro "0" cannot be used as an interrupt macro. If an interrupt is generated and it's
vector table entry has been defined but the macro it specifies has not, then an error will be
reported.

2.2 Enabling and Disabling Interrupts

Loading a vector table entry will not enable an interrupt for operation. The Enable Vector

(EV) command must be used for this purpose. When the EV command is used, it will enable the
interrupt source (specified with the command) to function. In the event that it is necessary to
disable an interrupt source, there is a Disable Vector (DV) command that functions in a similar
manner as the EV command.

In order to prevent multiple or continuous interrupts, as an interrupt is taken it is
automatically disabled. This means that the user must re-enable that interrupt using the EV
command before it will occur again.

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SMAC LAC-25 Technical Reference Manual

2.3 Interrupt Sources

The following table lists all the possible interrupt sources.

Interrupt Source Level / Vector Interrupt Source Level/Vector

Axis 0 Error 31 Reserved 15
Axis 1 Error 30 Reserved 14

Reserved 2 9 Reserved 13

Reserved 2 8 Reserved 12
Axis 0 Fault 27 Reserved 11
Axis 1 Fault 26 Reserved 10

Reserved 2 5 Reserved 9

Reserved 2 4 Reserved 8
Axis 0 Limit 23 Reserved 7
Axis 1 Limit 22 Reserved 6

Reserved 2 1 Reserved 5

Reserved 2 0 Reserved 4

Axis 0 IP/IR 19 Digital Input 3 3
Axis 1 IP/IR 18 Digital Input 2 2

Reserved 1 7 Digital Input 1 1

Reserved 1 6 Digital Input 0 0

Table 5. Macro Interrupt Sources.

The Axis Error interrupts indicate that the position following error for a given axis has
exceeded the limit set by the Set Error (SE) command. Normally, when this limit is exceeded, the
servo is disabled and the "Error" bit in that axis' status word is set. If the interrupt for this condition

is enabled, the "Error" bit will still be set but the servo will not be disabled.

The Axis Fault interrupts indicate that a fault condition (usually an over-temperature
condition) has arisen. Normally, when this condition is detected, the servo is disabled and the
"Fault" bit in that axis' status word is set. If the interrupt for this condition is enabled, the "Fault"

bit will still be set but the servo will not be disabled.

The Axis Limit interrupts indicate that either a Limit+ or Limit- condition for an axis has
been detected. Whether or not a limit input will be recognized is determined by the Limit On (LN)
and Limit Off (LF) commands. The action taken is determined by the Limit Mode (LM) command.

Digital Inputs 00 - 03 provide 4 levels of undedicated, user definable interrupts. T he
interrupt for a given input will be active when that input is active.

2.4 Interrupt Priority

If more than one interrupt source becomes active at the same time, then the source with
the higher level will be executed first. Level/vector 31 has the highest priority and level/vector 0
has the lowest priority.

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SMAC LAC-25 Technical Reference Manual

2.5 Interrupt Completion

Once an interrupt macro (or set of macros) has finished executing, a Return from Call (RC)
command or an undefined macro may be used to cause a return from the interrupting macro back
to the interrupted macro where command execution will continue from where it was interrupted
(see MS command). In cases where it is undesirable to return to the interrupted macro, the Unpush
Macro (UM) command can be used to remove the previously pushed macro from the macro stack.
This command can also be used to completely reset the macro stack in order that the user program
can be restarted.

2.6 Interrupt Latency

Interrupt sources are sampled before each command in a macro is executed. This means
that the amount of time that an interrupt is held off before execution (also known as interrupt
latency) depends on how long it takes the previous command to complete. For most commands this
delay will be imperceptible.

Commands such as Wait (WA), Wait for Edge (WE), Wait for Stop (WS), Wait for Off (WF),
Wait for On (WN) and Wait for Index (WI) would normally be a source of unacceptable delay in that
they can quite often be indeterminate in length. This problem has been avoided by making these
instructions interruptable. For example, if a WA10000 command (a 10 second delay) is currently i n
progress and an interrupt comes along, the remaining delay period will be saved and then returned
to after the interrupt has completed. If the interrupt were to take 3 seconds to execute, then the
total wait time of the WA10000 command would be extended to 13 seconds.

The Position Mode (PM), Torque Mode (QM), Velocity Mode (VM), Wait for Position
Absolute (WP) and Wait for Position Relative (WR) commands and any command that uses the
serial communications link are all commands that could cause unacceptable interrupt latency.
Therefore, their usage should be carefully considered where interrupts are possible.

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3. Entering Commands

Immediately after power-up, the LAC-25 is ready to accept commands. To verify this, you
can hit the ESC key. If everything is working properly, this should cause a greater than sign (">")
prompt to appear on your display. If not, you need to verify that the power and communications
connections are correct and verify the compatibility of the communications protocol.

Commands are entered via a "dumb" terminal or host computer such as a PC compatible.
Commands sent to the LAC-25 should consist of standard ASCII characters, and the command lines
should be followed by a carriage return. Linefeeds are not necessary since they are used for
formatting and therefore they are ignored. As characters are entered at the keyboard, they should
be echoed on your display. If your display echoes its own transmitted characters, you will want to
issue the Echo Off (EF) command; otherwise, the Echo On (EN) command (which is the default
mode) should be issued. If you enter an invalid command, the LAC-25 will respond with a question
mark "?" followed by a code indicating the type of error and the Status LED will begin to blink.
These codes are listed in Appendix A, LAC-25 Error Code Definitions.

If you make a mistake when entering a command, you can backspace to correct the error. If
you are entering commands and change your mind, hitting the ESC key will cancel the line and
give a new ">" prompt.

Once a command line has been entered and has finished executing, hitting the RETURN
key will cause the same command line to be re-executed. While a set of commands are
executing, hitting the space bar will cause command execution to pause until the space bar is hit
again. Also, if the ESC key is hit during execution or pause, command execution will be
terminated, and you will receive a new ">" prompt.

Command instructions are intended for use with the following syntax:

[Axis#]Command[Argument]<CR>

or...

[Axis#]Command[Argument],[Axis#]Command[Argument],...etc.

The axis number is normally specified as being from "1" to "2" with "0" being used to refer
to both axis' at the same time. Once an axis has been specified, the same one will remain in effect
until another is specified. For example, if the following were entered:

1SG100,SD500,SV1000000<CR>

or...

1SG100<CR>
SD500<CR>
SV1000000<CR>

the SG command specifies the axis number, so the subsequent SD and SV commands are
performed on the same axis. If the following command were issued:

0TP<CR>

it would have the same affect as issuing these commands:

1TP<CR>
2TP<CR>

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During interrupts and macro calls, the axis number is saved and then later restored. After an
interrupt macro entered or a macro call is taken, it is a good idea for the user to make sure an
axis number (if necessary) gets set during one of the first commands encountered.

The numerical range of an argument will vary depending on the command with which it is
used. The mathematical interpretation of the argument will depend on whether the Decimal Mode
(DM) or Hexadecimal Mode (HM) was the last issued (DM is the power on default). Both decimal
and hexadecimal numbers less than zero should be entered with a preceding minus "-" sign. If no
argument is given, then it will be assumed as "0". The exceptions to this are the Macro Define
(MD), Macro Jump (MJ), Macro Call (MC),Macro Sequence (MS), Reset Macro (RM) and Tell
Macro (TM), commands. It should be noted that commands can be strung together by using
commas, up to a maximum line length of 127 characters.

If a command line is ended by a ";" and a comment, i.e...

>SG1000,SD5000 ; Set filter gains.<CR>

then the ";" and anything following it to the end of the line will be ignored. This feature is not
particularly useful if you are entering commands manually, as comments are not retained by the
LAC-25. However, if commands are downloaded to the LAC-25 from a host computer, the ability for
line comments can make program documentation possible and desirable.

3.1 Downloading Commands

In many cases, it is more convenient to enter commands using a text editor on a host
computer and then download that text file to the LAC-25 using a communications program such as

ProComm or the Microsoft

used, it must have the ability to provide a short delay (approx. 100 mS) after transmitting each line
to give the LAC-25 time to interpret and store the commands that were just sent.

Windows Terminal program. Whatever communications software is



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4. Introduction to Commands

The LAC-25 command instructions are varied and consist of several categories of purpose.
The command descriptions will be detailed by these categories.

4.1 Parameter Commands

The parameter setting commands are considered to be those for setting the operating
conditions of the servo system (i.e. PID filter gains, velocity, acceleration and etc.).

Command: aDBn -- Dead-Band --

Argument: 0 <= n <= 16383
Default: 0

This command sets the position following error dead-band for servo axis 'a'. The purpose for
the DB command is to allow an acceptable static position error for which there will be no restoring
force. This has the affect of reducing or eliminating "hunting" which is the continuous movement
at or about a position in trying to seek that position. This is useful for applications that cannot
tolerate this condition. Please note that the DB command is only in effect when the servo is not in
motion (or when the Trajectory Complete bit is set in the servo status word).

Related Commands: TF

Command: aFAn -- Feed-forward, Acceleration --

Argument: 0 <= n <= 32767
Default: 0

This command allows for the adjustment of the PID digital filter acceleration feed-forward
term for servo axis 'a'.

During the course of a Position Mode (PM) or Velocity Mode (VM) move, at any point
during acceleration or deceleration (with a consistent load), the ideal required value of the servo
output is fairly consistent and somewhat predictable.

During acceleration or deceleration:

OUTPUT = (VELOCITY * FV_CONSTANT) + (ACCELERATION * FA_CONSTANT)

During constant velocity:

OUTPUT = (VELOCITY * FV_CONSTANT)

If this value can be dynamically predicted and summed with the output of the PID digital filter, i n
effect, it reduces the burden of the PID filter to make lead/lag corrections based of the following
error, thereby enhancing performance.

Related Commands: FV, OM, OO

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Command: FF -- Fail Input Off --

Default: Off

This command has no effect but is retained for backward compatibility purposes.

Command: FN -- Fail Input On --

Default: Off

This command has no effect but is retained for backward compatibility purposes.

Command: aFRn -- Set Derivative Sampling Period --

Argument: 0 <= n <= 127
Default: 0

This command allows for the adjustment of the derivative sampling interval for servo axis
'a'. The period of this interval can be calculated by the following:

T = (n+1) * S * 0.000100

where "T" is the period in seconds, "n" is the FR command argument and "S" is the sample period
count specified by the Servo Speed (SS) command. For example, if the value previously set by the
SS command is 10 and the value set by the FR command is 1, then the derivative sample period
will be:

(1+1) * 10 * 0.000100 = .002000 S or 2 mS

This command is useful in tuning the PID servo loop to the inertial properties of the system.

Related Commands: RI, SS

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SMAC LAC-25 Technical Reference Manual

Command: aFVn -- Feed-forward, Velocity --

Argument: 0 <= n <= 32767
Default: 0

This command allows for the adjustment of the PID digital filter velocity feed-forward term
for servo axis 'a'.

During the course of a Position Mode (PM) or Velocity Mode (VM) move, at any point along
the way (with a consistent load), the ideal required value of the servo output is fairly consistent and
somewhat predictable.

During acceleration or deceleration:

OUTPUT = (VELOCITY * FV_CONSTANT) + (ACCELERATION * FA_CONSTANT)

During constant velocity:

OUTPUT = (VELOCITY * FV_CONSTANT)

If this value can be dynamically predicted and summed with the output of the PID digital filter, i n
effect, it reduces the burden of the PID filter to make lead/lag corrections based of the following
error, thereby enhancing performance.

Related Commands: FA, OM, OO

Command: aGRn -- Gear Ratio --

Argument: -8388607 <= n <= 8388607
Default: 0

This command sets the electronic gearing ratio for axis 'n'. A negative argument will cause
a direction reversal in the electronic gearing. The argument to this command is the desired
gearing ratio scaled by 65536.

Examples:

GR65536 ; Slave gear ratio is 1:1
GR131072 ; Slave gear ratio is 2:1
GR32768 ; Slave gear ratio is .5:1
GR6554 ; Slave gear ratio is .1:1 (actual gear ratio is

; .100006103516:1).

GR-65536 ; Slave ratio is 1:1 with direction reversal

Related Commands: EG

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Command: aILn -- Set Integration Limit --

Argument: 0 <= n <= 16,383
Default: 0

This command clamps the level of influence that the PID digital filter integral term can use
to reduce the static position error of servo axis 'a'. When properly adjusted, this can enhance loop
stability and operation. The Integral Limit (IL) and Set Integral Gain (SI) must both be set to a non­zero value in order for the integral term to have any effect.

Related Commands: SI

Command: aLFn -- Limit Switch Input Off --

Argument: 0 <= n <= 3
Default: 0

This command disables one or more of the limit switch inputs for servo axis 'a'. The valid
arguments to this command determine which inputs will be disabled and are as follows:

n Limit Switch Inputs Disabled

0, 3 or no
argument

1 Limit+
2 Limit-

Limit+ and Limit-

Related Commands: LM, LN

Command: aLMn -- Limit Switch Input Mode --

Argument: 0 <= n <= 3
Default: 0

This command is used to select how the LAC-25 will react when a limit switch is activated
for servo axis 'a'. The valid arguments for this command are as follows:

n Action
0 Turn servo off, continue commands

1 Stop abruptly, continue commands
2 Decelerate smoothly, continue

commands

3 Interrupt only

In all cases, the Error flag in the status word will be set. This will prevent the LAC-25 from
moving the servo until the flag is cleared by issuing the Motor On (MN) command. Before this
command will have any effect, the limit switch must be enabled with the Limit Switch On
command (LN).

Related Commands: LF, LN

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Command: aLNn -- Limit Switch Input On --

Argument: 0 <= n <= 3

This command is used to enable one or both of the limit switch inputs for servo axis ÔaÕ.
Once enabled, the servo will be stopped or turned off if a limit switch input goes active. At the
same time the Limit Switch Tripped and Error Flags will be set in the status word. These flags will
remain set until the servo is turned back on with the Motor On (MN) command. Once the servo is
turned back on, it can be moved out of the limit switch region with any of the standard motion
commands. The argument to this command determines which of the limit switch inputs will be
enabled. The coding is as follows:

n Limit Switch Inputs Enabled
0,3 or no argument Limit+ and Limit-

1 Limit+
2 Limit-

Related Commands: LF, LM

Command: aOMn -- Output Mode --

Argument: 0 <= n <= 255
Default: 0

This command allows the user to determine what data gets sent to the D/A analog output
for a given axis. The upper four bits of the argument are for redirection of data and determine from
which axis the D/A channel will get itÕs data. This allows both D/A channels to output data from
the same axis. If no redirection is specified, the default data used is that of the current axis.

Note: When outputting the servo output command, if no redirection is specified, then the output

command as phase adjusted by the PH command will be output. If redirection is specified,

then the normalized data as reported by the TQ command will be output.

ÔnÕ Value Output

0 Servo Output Command
1 Servo Following Error Ôn+Õ Redirect Channel
2 Servo Following Error * 64 0 Default

3 Variable USER1 16 1
4 Low Bits of Encoder Position 32 2

5 Reserved
6 Reserved
7 Reserved

Examples:

1OM0 ; Send axis 1 servo output command to D/A channel 1.
1OM16 ; Send axis 1 servo output command to D/A channel 1.

2OM0 ; Send axis 2 servo output command to D/A channel 2.
2OM32 ; Send axis 2 servo output command to D/A channel 2.

1OM0 ; Send axis 1 servo output command to D/A channel 1.
2OM17 ; Send axis 1 following error to D/A channel 2.

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Command: aOOn -- Output Offset --

Argument: -32767 <= n <= 32767
Default: 0

This command allows the user to set a continuous output for servo axis ÔaÕ. In certain
applications, such as an overhanging load, there will be a continuous burden placed upon a servo
axis. In cases like these, where there is a predictable load, the OO command can be used to
provide a continuous restoring force that will be combined with the output of the PID digital filter.
This has the affect of improving the performance of the PID digital filter in that because it is not
saturated with static load, it has a better dynamic response to load disturbances.

Related Commands: FA, FV, OM

Command: aPHn -- Set Servo Phasing --

Argument: 0 <= n <= 63
Default: 0

This command is used to set the output polarity, encoder phasing, Index input sense, Home
input sense, Limit+ and Limit- input sense for servo axis ÔaÕ. The polarity of the output will determine
whether the servo is driven in a direction that reduces or increases position error. The encoder
phase will determine whether the position count will increase or decrease for a valid encoder input
sequence. The Index sense determines what logic edge will cause the Index input to be active.
The Limit+, Limit- and Home sense determines whether these signals are active ÒonÓ or active Òoff.

To determine the argument to be used with the PH command, use the follow table and add
the required values together.

Add to 'n'

Output Phase Normal 0
Output Phase Reversed 1
Encoder Phase Normal 0
Encoder Phase Reversed 2
Index Active Level Low 0
Index Active Level High 4
Home Sense Active "ON" 0
Home Sense Active "OFF" 8
Limit+ Sense Active "ON" 0
Limit+ Sense Active
"OFF"
Limit- Sense Active "ON" 0
Limit- Sense Active "OFF" 32

For example, if it were necessary to reverse the encoder phasing and to set the Limit+ and
Limit- inputs to active "OFF", then 'n' would be (2 + 16 + 32) or 50. The default phasing and sense
is equivalent to issuing this command with a argument of 0.

16

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Command: aRIn -- Sampling Rate of Integral --

Argument: 0 <= n <= 127
Default: 0

This command allows for the adjustment of the PID digital filter integral sampling interval
for servo axis 'a'. The period of this interval can be calculated by the following:

T = (n+1) * S * 0.000100

where "T" is the period in seconds, "n" is the RI command argument and "S" is the sample period
count specified by the Servo Speed (SS) command. For example, if the value previously set by the
SS command is 10 and the value set by the RI command is 1, then the integral sample period will
be:

(1+1) * 10 * 0.000100 = .002000 S or 2 mS

This command is useful in tuning the PID servo loop to the inertial properties of the system.

Related Commands: FR

Command: aSAn -- Set Acceleration --

Argument: 0 <= n < 1,073,741,823
Default: 0

This command sets the acceleration rate for servo axis 'a'. The 32 bit argument to this
command is scaled by 65536. This number determines how much the servo's velocity will be
altered by each servo loop interval (determined by the Servo Speed "SS" command) while it is
accelerating or decelerating. If this command is executed during a Position Mode move, it will be
ignored.

Example:

Encoder: 500 lines or 2000 Counts/Rev
Desired Acceleration: 75 Rev/Sec2
Servo Loop Interval: 1,000 Hz

9830.4 = ((75 Rev/Sec * 2000 Counts/Rev) / 1000 Hz2) * 65536

To achieve an acceleration of 75 Rev/Sec2, the command SA9830 would be issued. A
simpler way to calculate the acceleration argument would be to determine a constant for your
application by which to calculate desired acceleration.

131.072 = K = ((1 Rev/Sec * 2000 Counts/Rev) / 1000 Hz2) * 65536

9830.4 = 75 Rev/Sec * K

Please note that if the Set Acceleration (SA) command is used with an argument of "0",
then you have commanded the velocity to change in steps of zero which means if the servo is
stopped it will not be able to move, and if the servo is moving it will not be able to change velocity.

Related Commands: SS, SV

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Command: aSCn -- Set Current Mode Gain --

Argument: 0 <= n <= 32,767
Default: 0

This command sets the "current mode" gain for servo axis 'a' used by Torque Mode (QM1
only, see QM command). This allows the response of the current error integrator to be adjusted to
suit a given application. A low SC value will provide slow response to load changes while a high
SC value will provide quick response to load changes. If SC is set is too low then inadequate
control may occur. If the SC setting is too high then the system may be unstable. A good "general"
value for SC is about 8000.

Related Commands: QM, SQ

Command: aSDn -- Set Derivative Gain --

Argument: 0 <= n <= 32,767
Default: 0

This command sets the derivative gain term of the PID digital filter loop for servo axis 'a'.

Related Commands: SG, SI, IL

Command: aSGn -- Set Proportional Gain --

Argument: 0 <= n <= 32,767
Default: 0

This command sets the proportional gain term of the PID digital filter loop for servo axis 'a'.

Related Commands: SI, SD, IL

Command: aSIn -- Set Integral Gain --

Argument: 0 <= n <= 32,767
Default: 0

This command sets the integral gain term of the PID digital filter loop for servo axis 'a'. The
Set Integral Gain (SI) and Integral Limit (IL) must both be set to a non-zero value in order for the
integral term to have any effect.

Related Commands: SG, SD, IL

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Command: aSQn -- Set [Maximum] Torque Level --

Argument: -32,767 <= n <= 32,767 in Torque Mode 0 (QM0)

-1,023 <= n <= 1,023 in Torque Mode 1 (QM1)
0 <= n <= 32,767 in Position Mode (PM)
0 <= n <= 32,767 in Velocity Mode (VM)

Default: 32,767

For servo axis 'a', this command sets the maximum output level when in Position Mode (PM)
or Velocity Mode (VM) and sets the desired output level when in Torque Mode (QM). When this
command is issued in Position Mode (PM) or Velocity Mode (VM), its limiting effect will remain, in
all modes of operation, until again changed. Note that an argument less than zero is allowed only
in Torque Mode (QM).

Examples:

>PM,SQ20000<CR> ; Set maximum output to +-20000.

>VM,SQ10000<CR> ; Set maximum output to +-10000.

>QM,SQ20000<CR> ; Set output to forward 20000.

>QM,SQ-10000<CR> ; Set output reverse 10000.

>PM,SQ10000<CR> ; Set maximum output to +-10000.
>QM0,SQ15000<CR> ; Set output to forward 15000 but

Related Commands: PM, QM, SC, VM

; will only achieve output of 10000
; due to previous command.

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Command: SSn -- Set Servo Speed --

Argument: 1 <= n <= 255
Default: 2

This command sets the servo loop interval, which is the same for both axis' of the LAC-25.
The period of this interval can be calculated by the following:

T = (n) * 0.000100

where "T" is the period in seconds and "n" is the SS command argument. For example, if the
value set by the SS command is 10 then the servo loop period will be:

10 * 0.000100 = .001000 S or 1 mS

The minimum servo loop rate is 100 µS per enabled axis. The following table shows t he
minimum servo loop times:

# Axis

Enabled

0 100µS
1 100µS
2 200µS

Using the SS command affects the Set Velocity (SV) and Set Acceleration (SA) commands
in that they both are specified in terms of servo loop intervals. For example, if the servo loop rate is
doubled, the velocity and acceleration would appear to have been halved. It should also be noted
that the "SS" command will most likely affect the required settings of the PID digital filter.

Related Commands: SA, SV

Minimum Loop Time

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Command: aSVn -- Set Maximum Velocity --

Argument: 0 <= n < 1,073,741,823
Default: 0

This command sets the desired velocity (in quadrature counts per servo loop interval) for
servo axis 'a'. The 32 bit argument to this command consists of a 16 bit integer part and a 16 bit
fractional part.

Example:

Encoder: 500 lines, 2000 Counts/Rev
Desired Velocity: 40 Rev/Sec
Servo Loop Interval: 1,000 Hz

5242880 = ((40 Rev/Sec * 2000 Counts/Rev) / 1000 Hz) * 65536

To achieve a velocity of 40 Rev/Sec, the command SV5242880 would be issued. A simpler
way to calculate the velocity would be to determine a constant for your application by which to
calculate desired velocity.

131072 = K = ((1 Rev/Sec * 2000 Counts/Rev) / 1000 Hz) * 65536

5242880 = 40 Rev/Sec * K

Related Commands: SA, SS

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4.2 Reporting Commands

The reporting commands output data relevant to the operating status of the LAC-25.
Numerical output will be in the mathematical base determined by the Decimal Mode (DM) /
Hexadecimal Mode (HM) commands and output will be followed by a carriage return and linefeed.

Command: TAn -- Tell Analog to Digital Channel 'n' --

Argument: 0 <= n <= 9

This command will cause a conversion on A/D channel 'n' and will display the result.

Related Commands: GA

Command: aTB -- Tell Breakpoint --

Default: "None"

This command reports the last programmed breakpoint value specified by the Interrupt on
Position Absolute (IP) or the Interrupt on Position Relative (IR) commands for servo axis 'a'. If no
breakpoint value has yet been specified then the word "NONE is returned.

Related Commands: IP, IR

Command: TCn -- Tell State of I/O Channel 'n' --

Argument: 0 <= n <= 63
Default: "Off"

This command reports the current state of the I/O channel specified by 'n' and what type of
logic the channel is (either active "on" or active "off"). The display is formatted as follows:

/xx = aaa

The presence of the "/" character indicates that a channel is active in the "off" state. A lack
of the "/" character indicates that the channel is active in the "on" state. The "xx" indicates the
channel number and the "aaa" indicates the channel's current state, either "ON" or "OFF". T he
following examples show all the possible combinations:

01 = ON ; Channel 1 is "ON" in the active "ONÓ state.
/01 = ON ; Channel 1 is "ON" in the active "OFF" state.
01 = OFF ; Channel 1 is "OFF" in the active "ON" state.
/01 = OFF ; Channel 1 is "OFF" in the active "OFF" state.

Related Commands: CF, CH, CL, CN

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Command: aTD -- Tell Derivative Gain --

This command reports the derivative gain value of the PID digital filter for servo axis 'a'.

Related Commands: TG, TI, TL

Command: TE -- Tell Error --

This command reports the last error code caused by any command or macro. If no error has
occurred then a "0" will be reported. Once the TE command has been issued, then the error code
will be reset to zero. The TE command is useful for determining what error occurred in the case
that no display was connected at the time.

Command: aTF -- Tell Following Error --

This command reports the following error for servo axis 'a'. This value is the difference
between the current desired temporal position (or that which is reported by the Tell Optimal (TO)
command) of the trajectory generator and the servo's current real position (or that which is reported
by the Tell Position (TP) command).

Related Commands: DB

Command: aTG -- Tell Proportional Gain --

This command reports the proportional gain value of the PID digital filter for servo axis 'a'.

Related Commands: TI, TD, TL

Command: aTI -- Tell Integral Gain --

This command reports the integral gain value of the PID digital filter for servo axis 'a'.

Related Commands: TG, TD, IL

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Command: aTKn -- Tell (K) Constants --

Argument: 0 <= n <= 1

This command will display a number of internal settings depending on the value specified
by 'n'. If 'n' is "0" or is not specified, then various parametric values for the servo axis specified by 'a'
will be displayed. If 'n' is "1", then various system parameters will be displayed.

Example display for the command "1TK0":

>1TK0

Parameter Values for Axis [1]

Proportional Gain ---------- (SG) = 0
Integral Gain -------------- (SI) = 0
Derivative Gain ------------ (SD) = 0
Integral Limit ------------- (IL) = 0
Current Gain --------------- (SC) = 0
Velocity Feed-forward Gain - (FV) = 0
Accel. Feed-forward Gain --- (FA) = 0
Output Offset -------------- (OO) = 0
Position Error Dead-Band --- (DB) = 0
Maximum Following Error ---- (SE) = 16383
Integral Sample Rate ------- (RI) = 0
Derivative Sample Rate ----- (FR) = 0
Phase and Sense Settings --- (PH) = 0
Maximum Velocity ----------- (SV) = 0
Acceleration --------------- (SA) = 0
Desired Direction ---------- (DI) = 0
Torque (output) Limit ------ (SQ) = 32767
Axis Type ------------------ (OM) = 0

Example display for the command "TK1":

>TK1

System Parameter Settings (group 1).

Axis 1 Enabled ------------- (EA) = Yes
Axis 2 Enabled ------------- (EA) = Yes
Base 16 Input & Output -- (HM/DM) = Off
Character Echo ---------- (EN/EF) = On
Handshake --------------- (HN/HF) = Off
Fail -------------------- (FN/FF) = Off
Servo Loop Rate ------------ (SS) = 2
Input Debounce/Delay ------- (ID) = 0
Phase and Sense Settings --- (CV) = 0
Intr. Vector Enable, HIGH (EV/DV) = 0
Intr. Vector Enable, LOW (EV/DV) = 0
Firmware Revision ---------- (VE) = 3.30

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Command: aTL -- Tell Integration Limit --

This command reports the integration limit value of the PID digital filter for servo axis 'a'.

Related Commands: TG, TI, TD

Command: TMn -- Tell Macros --

Argument: -2 <= n <= 255

The Tell Macro (TM) command will display the commands which make up any macros that
have been defined. If 'n' >= 0 and 'n' <= 255, then the macro specified by 'n' be displayed. If 'n' = ­1, then all the macros will be displayed preceded by the individual macro number. If 'n' =-2, then
all macros will be displayed and will be preceded by the letters "MD" and the individual macro
number. This is useful when downloading programs from the LAC-25 to a computer in that you
need not re-enter the Macro Define (MD) command and number at the beginning of each macro.

Related Commands: MD, RM

Command: aTO -- Tell Optimal Position --

This command reports the desired position for servo axis 'a'. This value may be different
from the position reported by the TP command if the servo is moving or the controller is unable to
drive the servo.

Related Commands: TT, TP

Command: aTP - Tell Real Position --

This command reports the absolute position of servo axis 'a'. It may be used to monitor
motion during both the Motor On (MN) and the Motor Off (MF) states.

Related Commands: TT, TO

Command: aTQ -- Tell Torque --

his command reports the current output torque being commanded for servo axis 'a'. This
value will be either that which is generated by the PID output or which is set by the user via the
Torque Mode (QM).

Command: TRn -- Tell Contents of Register 'n' --

Argument: 0 <= n <= 511

This command reports the value contained by Register 'n'.

Related Commands: Register Commands

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Command: aTS -- Tell Status Word --

This command reports the operating status word of servo axis 'a'. The response is coded into
a single 32 bit value. The meaning of each bit is listed below:

Bit Purpose

0 Servo Enabled. This bit will be set to Ò1Ó when the servo is enabled

via the Motor On (MN) command. A Ò0Ó indicates that the servo has
been disabled via one of the following reasons: a Motor Off (MF)
command, a servo error due to excessive following error or over
temperature condition, a limit event, an external fault.

1 Servo Error. A Ò1Ó in this bit position indicates that the maximum

servo following error or over-temperature condition has occurred, or
the external fault has been activated.

2 Over Temperature. A Ò1Ó in this bit position indicates that an over-

temperature condition has occurred or the external fault input has
been activated.

3 Breakpoint Reached. A Ò1Ó in this bit position indicates that a

previously defined breakpoint has been reached. This bit will be reset
by any of the following commands: Motor On (MN), Interrupt on
Position (IR), Interrupt on Relative Position (IR).

4 Trajectory Complete. A Ò1Ó in this bit position indicates that the servo

has completed a commanded move. A Ò0Ó indicates that the servo is
busy executing a commanded move.

5 Servo Stopping. A Ò1Ó in this bit position indicated that the servo has

been commanded to stop. Upon stopping, this bit is then cleared.

6 Current Direction. This bit indicated the current direction of travel for

the servo. (0 = Positive, 1 = Negative)

7 Desired Direction. This bit indicates the direction commanded by

the Direction (DI) command. (0 = Positive, 1 = Negative)
8 Reserved.
9 Reserved.
10 Looking for Index. A Ò1Ó in this bit position indicates that the IMCSA

is currently watching for an index pulse to occur as commanded by

the Find Index (FI) command.
11 Looking for Edge. A Ò1Ó in this bit position indicates that the IMCSA

is currently watching for the Coarse Home input to go active as

commanded by the Find Edge (FE) command.
12 Reserved.
13 Coarse Home Input Active. A Ò1Ó in this bit position indicates that the

Coarse Home input is active.
14 Capture Index Flag. A Ò1Ó in this bit position indicates that the Find

Index (FI) command is trying to capture the position on occurrence of

an index pulse as opposed to initializing the position.
15 Reserved.
16 Accelerating.? A Ò1Ó in this bit position indicates that the servo is

currently accelerating.
17 Position Mode. A Ò1Ó in this bit position indicates that the servo is

currently operating in position mode.
18 Velocity Mode. A Ò1Ó in this bit position indicates that the servo is

currently operating in velocity mode.
19 Torque Mode. A Ò1Ó in this bit position indicates that the servo is

currently operating in (voltage) torque mode.
20 Current Mode. A Ò1Ó in this bit position indicates that the servo is

currently operating in (current) torque mode).
21 Reserved.

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22 Electronic Gearing Mode. A Ò1Ó in this bit position indicates that the

servo is currently operating in electronic gearing mode.
23 Reserved.
24 Limit Mode Abort. Used by Limit Mode (LM) to determine what action

to take upon the occurrence of a limit switch event.
25 Limit Mode Stop. Used by Limit Mode (LM) to determine what action

to take upon the occurrence of a limit switch event.
26 Limit- Tripped. A Ò1Ó in this bit position indicates that a Limit- input

event has occurred and has been acted upon as set by the Limit

Mode (LM) command.
27 Limit- Enabled. A Ò1Ó in this bit position indicates that the Limit- input

has been enabled for action via the Limit Mode (LM) command.
28 Limit- Active. A Ò1Ó in this bit position indicates that the Limit- input is

currently active.
29 Limit+ Tripped. A Ò1Ó in this bit position indicates that a Limit+ input

event has occurred and has been acted upon as set by the Limit

Mode (LM) command.
30 Limit+ Enabled. A Ò1Ó in this bit position indicates that the Limit+

input has been enabled for action via the Limit Mode (LM)

command.
31 Limit+ Active. A Ò1Ó in this bit position indicates that the Limit+ input

is currently active.

Command: aTT -- Tell Target Position --

This command reports the current target position of servo axis 'a'. This is the absolute
position to which the servo was last commanded to move. It may have been specified directly with
the Move to Position (MP) or Move Absolute (MA) commands or indirectly with the Move Relative
(MR) command. If the servo axis is in Velocity Mode (VM), then the target position will track the
current optimal position (or that which is reported by the Tell Optimal (TO) command).

Related Commands: TO, TP

Command: aTV -- Tell Current Velocity --

This command reports the trajectory generator current velocity for servo axis 'a'. The value
reported has the same units as the Set Velocity (SV) command. See the description of that
command for further details.

Related Commands: SV, SS

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Command: VE -- Tell Version --

This command reports the firmware revision level. This revision level exists as a code in the
internal RAM memory (see Register Commands). This code should be interpreted as the first byte
being the major revision number and second byte being the minor revision number. This allows
user programs to determine the firmware revision for compatibility purposes.

Related Commands: Register Commands

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4.3 Motion Commands

Motion Commands are those commands that involve or cause the actual movement of a
servo. Any position mode (PM) based motion will be carried out using a trapezoidal velocity profile
with the maximum velocity determined by the Set Velocity (SV) command. The acceleration and
deceleration are the same and both are determined by the Set Acceleration (SA) command.

During the execution of a Position Mode based motion, the target position (MA or MR) and

the maximum velocity (SV) may be changed at any time, however, changes to the acceleration
(SA) will be ignored. If a velocity mode (VM) based motion is under way, the maximum velocity

(SV) and the acceleration (SA) may be changed at any time. During this type of motion, the target
position will continuously be set equal to the current optimal position. If a torque mode (QM) based
motion is under way, the torque setting (SQ) may be changed at any time. During this type of
motion, the target and optimal positions will continuously be set equal to the current real position.
In either PM, VM or QM, a Stop (ST) or Abort (AB) command will cause motion for the specified
servo axis to cease. If a servo axis is in Position Mode (PM) and is commanded into Velocity Mode
(VM), the motion will continue (only with no target destination) at the current maximum velocity set
by the Set Velocity (SV) command. If a servo axis is in PM or VM and commanded into Torque
Mode (QM), the servo output will be reduced to zero, and the unit will be placed in QM. If a servo
axis is in VM and commanded into PM, the servo will be stopped at the current acceleration rate
and placed into the PM mode. If a servo axis is in QM and commanded into VM, it will attempt to
instantly assume the last known maximum velocity and remain in VM. If a servo axis is in QM and
commanded into PM, the output will be reduced to zero, and the servo will begin station keeping
in PM.

There is another mode of operation referred to as "Electronic Gearing Mode". This mode is
a supplement to the position based modes of operation. Electronic gearing causes the servo axis
for which it is in effect (or the slave axis), to move proportionally to the servo axis it is tracking (or
the master axis) in conjunction with it's own motion profile. The proportion of the slave axis it set by
the Gear Ratio (GR) command.

When the EG command is issued, the relative position of the master axis (from the time of
the EG command), is monitored by the slave axis. This relative motion is multiplied by the value
set with the GR command and the product of which is added to the optimal temporal position of
the slave axis. The result of this is to allow the motion profile of the master servo axis to b e
superimposed on the slave axis' motion profile. While the EG mode is primarily intended for use
with axis' that are operating in position mode (PM), it will also work with axis' that are operating i n
velocity mode (VM).

Command: aAB -- Abort Motion --

This command causes an emergency stop on servo axis 'a'. The servo stops abruptly but
leaves the servo control loop enabled. The target position is changed to be equal to the present
position. The command is used for stopping an undesired motion.

Related Commands: ST

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SMAC LAC-25 Technical Reference Manual

Command: aCI -- Capture on Index --

This command causes the position counter of servo axis 'a' to be stored in the internal
variable HREG upon receipt of an index pulse. For more information on HREG, see the Register
Commands and the listing of the internal variables.

Related Commands: FI, WI

Command: aDA -- Enable Axis for Operation --

Default: Axis 1 and 2 enabled.

This command will disable operation of servo axis 'a'. Because no operation may be made
on a disabled axis, the equivalent of a Motor Off (MF) command is executed before the axis is
disabled.

Related Commands: EA

Command: aDHn -- Define Home --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command causes the current position of the servo axis 'a' to be defined as 'n'. From
then on, all positions used and reported for the servo axis will be relative to that physical position.

Related Commands: FE, FI

Command: aDIn -- Set Direction --

Argument: n = 0 for positive, n = 1 for negative
Default: 0

This command sets the move direction for servo axis 'a' when in velocity mode. Issuing this
command with an argument of "0" will cause the servo to move in a positive direction while an
argument of "1" will cause it to move in a negative direction.

Related Commands: SA, SV, VM

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Command: aEA -- Enable Axis for Operation --

Default: Axis 1 and 2 enabled.

This command will enable operation of servo axis 'a'. If an axis is not enabled for operation,
no system resources will be expended on it. For example, this means that if an axis is going to be
used for it's encoder interface only, it must still be enabled for operation via the EA command,
however, the undedicated encoder interface is always enabled and does not apply here.

Before using the EA command, one should be sure that the Set Servo Speed (SS)
command has been used such that the servo loop time is long enough to service the newly
enabled axis as well as any previously enabled axis'.

Related Commands: DA

Command: aEGn -- Electronic Gearing Mode --

Argument: -2 <= n <= 2
Default: Position Mode

This command causes (slave) servo axis 'a' to begin to move proportionally to (master) servo
axis 'n'. If 'n' is "0" then the electronic gearing mode for axis 'a' will be disabled. If 'n' is positive
then the slave axis will track the master axis' optimal position (or that which is reported by the TO
command). If 'n' is negative then the slave axis will track the master axis' real position (or that which
is reported by the TP command). It is preferable that the EG command only be used when the
target (or slave) axis is not in motion.

Related Commands: GR

Command: aFEn -- Find Edge of Coarse Home Input --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command is used to initialize servo axis 'a' at a given position. It will remain in effect
until the Home input goes active. At that time, the current position of the servo will be defined as
'n'. This command will neither start nor stop any servo motion. It is up to the user to initiate servo
motion before issuing the command and to stop any motion after the command is completed.

Related Commands: WE

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Command: aFIn -- Find Edge of Index --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command is used to initialize servo axis 'a' at a given position. It will remain in effect
until the Index input goes active. At that time, the current position of the servo will be defined as
'n'. Like the Find Edge (FE) command, this command will not start or stop any servo motions; that is
up to the user. Since an index pulse may occur at numerous points of the servo's travel (once per
revolution in rotary encoders), a typical application will require a home signal to establish a coarse
position reference before the index pulse can be used to fine tune that reference.

Related Commands: CI, WI

Command: aGH -- Go Home --

This command causes servo axis 'a' to move to absolute position 0. This is equivalent to a
Move Absolute (MA) command when the destination is 0. This command will initiate motion;
therefore, a Go (GO) command is not required.

Related Commands: MA, GO

Command: aGO -- Go (start motion) --

This command causes servo axis 'a' to begin motion. When in the Velocity Mode (VM), the
axis will accelerate to a constant velocity. When in the Position Mode (PM) the axis will begin to
seek the specified target position. The servo must be in the "on" state for motion to occur.

Related Commands: MA, MR, PM, VM

Command: aMAn -- Move Target Absolute --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command sets the target position of servo axis 'a' to absolute position 'n'. The absolute
position is relative to the point of initialization (home or 0). As the Move Absolute (MA) command
will not initiate a motion, a Go (GO) command must be used. The servo's target position will be
adjusted whether the servo is on or off.

Related Commands: GO, MR, PM

Command: aMF -- Motor Off --

This command is used to place servo axis 'a' in the "off" state. The servo's output will go to
the null level. This command can be used to prevent unwanted motion or to allow manual
positioning of the unit. When the servo is turned off, the target and the optimal positions will follow
the real position.

Related Commands: MN

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Command: aMN -- Motor On --

This command is used to place servo axis 'a' in the "on" state. When the servo is turned on,
its target position is set to its current position so that the servo is not inclined to move. When this
command is issued, it will disable the Home and Index interrupt sources and will reset the Error,
Fault, Breakpoint reached, Looking for Edge, Looking for Index and Limit Tripped bits in the status
word for axis 'a'.

Related Commands: LM, LN, MF

Command: aMRn -- Move Target Relative --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command generates a relative target position of 'n' counts for servo axis 'a'. Since the
Move Relative (MR) command will not initiate a motion, a Go (GO) command must be used. The
servo's target position will be adjusted whether the servo is on or off.

Related Commands: GO, MA, PM

Command: aPM -- Enter Position Mode --

Default: Position mode

This command causes servo axis 'a' to enter the position mode of operation. In this mode,
the servo can be commanded to move to a specific target position. The moves will be executed
using a trapezoidal velocity profile based upon parameters set by the Set Velocity (SV) and the Set
Acceleration (SA) commands.

Related Commands: EG, QM, VM

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Command: aQMn -- Enter Torque Mode --

Argument: 0 for voltage mode, 1 for current mode
Default: Position mode

This command places servo axis 'a' in the Torque Mode of operation. For mode 0 (or QM0),
the output PWM duty cycle (or analog output for appropriate models) can be manually controlled
by the user program. Once QM0 has been entered, the Set Torque (SQ) command can be used to
set or change the servo output (see the SQ command). Bear in mind, that if the output was being
limited by an SQ command before entering torque mode (while in PM or VM), it will remain limited
while in QM and cannot be changed until the unit is in PM or VM.

For mode 1 (or QM1), the LAC-25 will use one of its A/D channels to monitor servo output
current and attempt to maintain that output current at a steady level as commanded by the user
program (see the SQ and SC commands). In that the A/D converter has 10-bit resolution, this will
result in a value from 0 to 1023 which represents the instantaneous output current with 0 being
approximately 0 Amps and 1023 being approximately 5 Amps with intermediate values being
somewhat linear.

In the case of a motor (for example), when an output command of 512 is set (or about 2.5
amps), the PWM output begins to ramp up until the desired output current is reached. If the motor is
not loaded enough to require 2.5 amps then the PWM will ramp up to 100% putting the maximum
supply voltage to the motor. If at this point the motor is suddenly loaded, the PWM will ramp down
to a level sufficient to supply 2.5 amps to the motor.

Mode QM1 will not function with the D/A module option.

Related Commands: EG, PM, VM

Command: aSEn -- Set Maximum Following Error --

Argument: 0 <= n <= 16,383
Default: 16,383

This command is used to set the maximum allowable following error (difference between
the actual position and the optimal position) for servo axis 'a'. If the following error exceeds the
programmed value, the servo will be turned off (except in the case of the related interrupt being
enabled) and the Error bit in the status word for axis 'a' will be set. This bit will remain set until the
servo is turned back on with the Motor On (MN) command.

Related Commands: DB, TF

Command: aST -- Stop Motion --

This command is used to terminate motion on servo axis 'a'. This command differs from the
Abort (AB) command in that the servo will decelerate at its preset rate instead of stopping abruptly.
When in Torque Mode, the outputs will be set to null.

Related Commands: AB, WS

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Command: aVM -- Enter Velocity Mode --

Default: Position mode

This command places servo axis 'a' in the Velocity Mode of operation. In this mode, the
servo can be commanded to move in either direction to a maximum velocity. The servo will move
in that direction until commanded to stop. When using Velocity Mode, the user must specify the
direction for the servo to move using the Direction (DI) command. After specifying the desired
maximum velocity and the desired direction and placing the servo in velocity mode, the servo ca n
be started by issuing the Go (GO) command. While the servo is moving in Velocity Mode, the user
can change the velocity by issuing new Direction (DI) and/or Set Velocity (SV) commands. The
acceleration rate at which the servo's velocity will change, is determined by the Set Acceleration
(SA) command. The acceleration can also be changed at any time.

Related Commands: EG, QM, PM

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4.4 Register Commands

The LAC-25 uses part of its nonvolatile RAM (NVRAM) to create a 512 by 32 bit general
purpose register space with Register "0" being referred to as the Accumulator.

The registers have many uses including storing data and parameters, performing
mathematical operations and controlling command execution. The registers can be manipulated
by several commands and can also be used to replace the argument in most commands. For
example, if register "6" contains the value "-12000" and the following command is used...

MA@6,GO

it would use the contents of register "6" as the argument thus giving the same result as if the
following command was issued...

MA-12000

Note that the use of the "@" character is what caused the command to assume a register
argument (or indirect argument) instead of a direct argument. If the value following the "@" is not
in the range of the 512 registers (0 to 511), an error will be reported. If the value contained by the
register of the indirect argument is out of range, an error will also be reported.

As stated earlier, because the registers are within the NVRAM, they are non-volatile and can
be used as such. For example, if a register is incremented once every user program cycle, it can be
used as an ongoing cycle counter for maintenance purposes, production accounting and etc.

4.4.1 Internal Variables

In certain applications, the user may find it necessary to use data pertinent to the internal
operation of the LAC-25. This may be accomplished via the use of the Read Byte (RB), the Read
Word (RW) and the Read Long (RL) commands which copy the LAC-25's internal RAM memory to
the accumulator and the Write Byte (WB), the Write Word (WW) and the Write Long (WL) commands
which copy the accumulator to the LAC-25's internal RAM memory. The listings below tell the
location of and describe the internal variables that may be of use to the user.

WARNING: Randomly modifying these variables or other internal RAM not listed will most

likely affect the operation of the LAC-25 resulting in unpredictable behavior or
possible damage.

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Axis Variable Descriptions.

Status Status word (TS command).
PV Peak velocity (SV command).
MPV Negative peak velocity (SV command).
V Temporal velocity (TV command).
Desp Desired position (TT command).
Carp Temporal desired position (TO command).
Ack Acceleration constant (SA command).
Curp Current real position (TP command).
HREG Holding register (CI,IP,IR commands).
IPPOS Interrupt on position reference.
QI Integral of current mode error (QM1 command).
PGAIN Proportional term of PID filter (SG command).
IGAIN Integral term of PID filter (SI command).
DGAIN Derivative term of PID filter (SD command).
IL Integral limit of PID filter (IL command).
CGAIN Current mode gain (QM1 command).
FVGAIN Velocity feed-forward of PID filter (FV command).
BIAS Output offset (OO command).
THRO Current servo output (TQ,SQ command).
QCMD Current command (QM1,SQ command).
TLMTPL Maximum positive servo output (SQ command).
FAGAIN Acceleration feed-forward of PID filter (FA command).
PERR Last calculated servo position error (TF command).
OERR Old servo position error.
MAXERR Maximum servo position error (SE command).
I Servo error integral.
DERIV Servo error derivative.
IMON Servo output current monitor.
INTRVL PID derivative sample interval (FR command).
SMPCNT PID derivative sample counter.
IINTRVL PID integral sample interval (RI command).
ISMPCNTPID integral sample counter.

AXIS Axis number lookup index.
ATYPE Axis output type (OM command).
PHASE Phase, sense and polarity information (PH command).
GMAxis Gear mode "gear to" axis (EG command).
DBAND Position error dead-band (DB command).
DERR Position error with dead-band.
GMOFF Gear mode initial position offset (EG command).
RATIO Gear mode gear ratio (GR command).
USER1 User variable #1 (See OM command).
FCNT Fault system counter.
FCMP Fault system comparator.
TLMTMI Maximum negative servo output (SQ command).

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System Variable Descriptions

RecRate Data recorder sample rate.
RecAddr Data recorder sample address source.
RecSize Data recorder sample data size.
AIN0 Analog Input 0. (After TA0,GA0 command).
AIN1 Analog Input 1. (After TA1,GA1 command).
AIN2 Analog Input 2. (After TA2,GA2 command).
AIN3 Analog Input 3. (After TA3,GA3 command).
AIN4 Analog Input 4. (After TA4,GA4 command).
AIN5 Analog Input 5. (After TA5,GA5 command).
AIN6 Analog Input 6. (After TA6,GA6 command).
AIN7 Analog Input 7. (After TA7,GA7 command).
AIN8 Analog Input 8. (After TA8,GA8 command).
AIN9 Analog Input 9. (After TA9,GA9 command).
VERSION Version number for program use. (VE command).
LST_ERR Last error code (TE command).
LTIMER 1 Hz LED timer.
ADSEMA A/D Interrupt system semaphores flags.
SYSSTAT System status word.
IPEND0 User interrupt pending level 0 -15 (EV,DV command).
IPEND1 User interrupt pending level 16 - 31 (EV,DV command).
SCLOCK Servo loop counter.
RCLOCK 1 mS Real time clock/counter.
IO_DELAY User digital input delay (ID command).

SYSSTAT Variable Bit Definitions

Bit Purpose

0 Axis 0 Enabled. This bit is set to Ò1Ó when axis 0 is enabled.
1 Axis 1 Enabled. This bit is set to Ò1Ó when axis 1 is enabled.
2 Reserved.
3 Reserved.
4 Reserved.
5 Pause. This bit is set to Ò1Ó when the space bar is used to pause a user program.
6 SXOff. This bit is set to Ò1Ó when the LAC-25 receives an XOFF code.
7 HexMod. This bit is set to Ò1Ó by the HM command and set to Ò0Ó by the DM

command.
8 Echo. This bit is set to Ò1Ó by the EN command and set to Ò0Ó by the EF command.
9 HandSh. This bit is set to Ò1Ó by the HN command and set to Ò0Ó by the HF

command.

10 Reserved.
11 Reserved.
12 Reserved.
13 Reserved.
14 Fail. This bit is set to Ò1Ó by the FN command and set to Ò0Ó by the FF command.
15 BadInp. This bit is set to Ò1Ó by the VI command to indicate an error in user input.

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Axis Variable Locations

Variable

Name

Status LONG
PV LONG
MPV LONG
V LONG
Desp LONG
Carp LONG
Ack LONG
Curp LONG
HREG LONG
IPPOS LONG
QI LONG
PGAIN WORD
IGAIN WORD
DGAIN WORD
IL WORD
CGAIN WORD
FVGAIN WORD
BIAS WORD
THRO WORD
QCMD WORD
TLMTPL WORD
FAGAIN WORD
PERR WORD
OERR WORD
MAXERR WORD
I WORD
DERIV WORD
IMON WORD
INTRVL BYTE
SMPCNT BYTE
IINTRVL BYTE
ISMPCNT BYTE
AXIS WORD
ATYPE BYTE
PHASE BYTE
GMAxis BYTE
DBAND WORD
DERR WORD
GMOFF LONG
RATIO LONG
USER1 WORD
FCNT WORD
FCMP WORD
TLMTMI WORD

Type Axis #1 Address Axis #2 Address

01C0H/0448 0250H/0592
01C6H/0454 0256H/0598
01CAH/0458 025AH/0602
01CEH/0462 025EH/0606
01E0H/0480 0270H/0624
01E6H/0486 0276H/0630
01EAH/0490 027AH/0634
01EEH/0494 027EH/0638
01F8H/0504 0288H/0648
01FCH/0508 028CH/0652
0200H/0512 0290H/0656
0204H/0516 0294H/0660
0206H/0518 0296H/0662
0208H/0520 0298H/0664
020AH/0522 029AH/0666
020CH/0524 029CH/0668
020EH/0526 029EH/0670
0210H/0528 02A0H/0672
0212H/0530 02A2H/0674
0214H/0532 02A4H/0676
0216H/0534 02A6H/0678
0218H/0536 02A8H/0680
021AH/0538 02AAH/0682
021CH/0540 02ACH/0684
021EH/0542 02AEH/0686
0220H/0544 02B0H/0688
0222H/0546 02B2H/0690
0224H/0548 02B4H/0692
0226H/0550 02B6H/0694
0227H/0551 02B7H/0695
0228H/0552 02B8H/0696
0229H/0553 02B9H/0697
022AH/0554 02BAH/0698
022CH/0556 02BCH/0700
022EH/0558 02BEH/0702
022FH/0559 02BFH/0703
0230H/0560 02C0H/0704
0232H/0562 02C2H/0706
0234H/0564 02C4H/0708
0238H/0568 02C8H/0712
0240H/0576 02D0H/0720
0242H/0578 02D2H/0722
0244H/0580 02D4H/0724
0246H/0582 02D6H/0726

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System Variable Locations

Variable
Name

RecRate WORD
RecAddr WORD
RecSize WORD
AIN0 WORD
AIN1 WORD
AIN2 WORD
AIN3 WORD
AIN4 WORD
AIN5 WORD
AIN6 WORD
AIN7 WORD
AIN8 WORD
AIN9 WORD
VERSION WORD
LST_ERR BYTE
LTIMER WORD
ADSEMA WORD
SYSSTAT WORD
IPEND0 WORD
IPEND1 WORD
SCLOCK LONG
RCLOCK LONG
IO_DELAY BYTE

Type Address

01A6H/422
01A8H/424
01AAH/426
0600H/1536
0602H/1538
0604H/1540
0606H/1542
0608H/1544
060AH/1546
060CH/1548
060EH/1550
0610H/1552
0612H/1554
0616H/1558
0619H/1561
061AH/1562
061CH/1564
0712H/1810
0718H/1816
071AH/1818
0722H/1826
0726H/1830
073EH/1854

Command: AAn -- Add 'n' to Accumulator (Signed) --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command adds the value 'n' to the accumulator.

Command: AC -- Accumulator Complement --

This command causes a (bit-wise) 1's complement of the accumulator.

Command: ADn -- Accumulator Divide by 'n' (Signed) --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command performs a 64 bit by 32 bit signed division with a 64 bit quotient and a 32
bit remainder. The low order 32 bits of the numerator must be in the accumulator and the high
order 32 bits must be in Register 1. The divisor is specified by 'n'. The lower 32 bits of the
quotient will be stored in the accumulator and the upper 32 bits will be stored in Register 1. The
remainder will be in Register 2.

Related Commands: AM

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Command: AEn -- Exclusive-Or Accumulator with 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command causes the result of an exclusive-OR of the accumulator with 'n' to reside in
the accumulator.

Command: ALn -- Load Accumulator with 'n' (Signed) --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command causes the accumulator to be loaded with the value 'n'.

Command: AMn -- Multiply Accumulator by 'n' (Signed) --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command does a signed multiply of the 32 bit contents of the accumulator and 'n',

leaving the lower 32 bits of the 64 bit product in the accumulator and the upper 32 bits in
Register 1.

Related Commands: AD

Command: ANn -- And Accumulator with 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command causes the result of the accumulator ANDed with 'n' to reside in the
accumulator.

Command: AOn -- Or Accumulator with 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command causes the result of the accumulator ORed with 'n' to reside in the
accumulator.

Command: ARn -- Copy Accumulator to Register 'n' --

Argument: 0 <= n <= 511

This command causes the value in the accumulator to be copied to Register 'n'.

Related Commands: RA

Command: ASn -- Subtract 'n' from Accumulator (Signed)

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command causes the value 'n' to be subtracted from the accumulator.

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Command: RAn -- Copy Register 'n' to Accumulator --

Argument: 0 <= n <= 511

This command causes the value in Register 'n' to be copied to the accumulator.

Related Commands: AR

Command: RBn -- Read Byte (8 bits) at RAM location 'n'

Argument: 0 <= n <= 2047

This command reads the 8 bit value at internal RAM location 'n' and copies it to the low 8­bits of the accumulator while clearing the upper 24 bits.

Related Commands: RW, RL, WB, WL, WW

Command: RLn -- Read Long (32 bits) at RAM location 'n' --

Argument: 0 <= n <= 2046

This command reads the 32 bit value at internal RAM location 'n' and copies it to the
accumulator. The value specified by 'n' must be evenly divisible by 2.

Related Commands: RB, RW, WB, WL, WW

Command: RWn -- Read Word (16 bits) at RAM location 'n' --

Argument: 0 <= n <= 2046

This command reads the 16 bit value at internal RAM location 'n' and copies it to the low
16-bits of the accumulator while clearing the upper 16 bits. The value specified by 'n' must be
evenly divisible by 2.

Related Commands: RB, RL, WB, WL, WW

Command: SLn -- Shift Accumulator Left 'n' bits --

Argument: 0 <= n <= 31

This command causes the accumulator to be shifted left 'n' bits while filling the low order
bits with zero.

Related Commands: SR

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Command: SRn -- Shift Accumulator Right 'n' bits --

Argument: 0 <= n <= 31

This command causes the accumulator to be shifted right 'n' bits while filling the high order
bits with zero.

Related Commands: SL

Command: TRn -- Tell Contents of Register 'n' --

Argument: 0 <= n <= 511

This command reports the value contained by Register 'n'.

Command: WBn -- Write Byte (8 bits) to RAM location 'n' --

Argument: 0 <= n <= 2047

This command copies the low 8-bits of the accumulator to the internal RAM location 'n'.

Related Commands: RB, RL, RW, WL, WW

Command: WLn -- Write Long (32 bits) to RAM location 'n' --

Argument: 0 <= n <= 2046

This command copies all 32 bits of the accumulator to the internal RAM location 'n'. The
value of 'n' must be evenly divisible by two.

Related Commands: RB, RL, RW, WB, WW

Command: WWn -- Write Word (16 bits) to RAM location 'n' --

Argument: 0 <= n <= 2046

This command copies the low 16-bits of the accumulator to the internal RAM location 'n'.
The value of 'n' must be evenly divisible by two.

Related Commands: RB, RL, RW, WB, WL

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4.5 Sequence Commands

The LAC-25 includes commands that provide for conditional sequence command
execution based on the register data, I/O state and etc. These Sequence Commands are illustrated
by the following general forms:

• If the condition is true, command execution will continue normally. If the condition is

false, the next two commands in the command line or the macro will be skipped.

• If the condition is true, command execution will continue normally. If the condition is

false, the rest of the command line or the macro will be skipped.

• If the condition is true, command execution will continue normally. If the condition is

false, command execution will be suspended until the condition becomes true.

Command: DFn -- Do if I/O Channel is "Off" --

Argument: 0 <= n <= 63

This command will cause command execution to continue if I/O channel 'n' is "Off";
otherwise, the rest of the command line or the macro will be skipped.

Related Commands: CF, CN, DN

Command: DNn -- Do if I/O Channel is "On" --

Argument: 0 <= n <= 63

This command will cause command execution to continue if I/O channel 'n' is "On";
otherwise, the rest of the command line or the macro will be skipped.

Related Commands: CF, CN, DF

Command: EP -- End Program --

This command will cause program execution to cease and return the ">" prompt.

Related Commands: RC

Command: IBn -- If Accumulator is Below 'n' (Signed) -

Argument: -2,147,483,647 <= n <= 2,147,483,647

If the contents of the accumulator is less than (signed comparison) the value 'n', command
execution will continue; otherwise, the next two commands in the command line or the macro will
be skipped.

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Command: ICn -- If Bit 'n' of Accumulator is Clear (0) --

Argument: 0 <= n <= 31

If bit 'n' of the accumulator is clear (equals 0), command execution will continue; otherwise, the
next two commands in the command line or the macro will be skipped.

Command: IEn -- If Accumulator Equal to 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

If the accumulator is equal to the value 'n', command execution will continue; otherwise,
the next two commands in the command line or the macro will be skipped.

Related Commands: IU

Command: IFn -- If I/O Channel is "Off" --

Argument: 0 <= n <= 63

If the I/O channel specified by 'n' is in the "off" state, command execution will continue;
otherwise, the next two commands in the command line or the macro will be skipped.

Related Commands: CF, CN, IN

Command: IGn -- If Accumulator is ">" 'n' (Signed) --

Argument: -2,147,483,647 <= n <= 2,147,483,647

If the contents of the accumulator is greater than (signed comparison) the value 'n',
command execution will continue; otherwise, the next two commands in the command line or the
macro will be skipped.

Command: INn -- If I/O Channel is "On" --

Argument: 0 <= n <= 63

If the I/O channel specified by 'n' is in the "on" state, command execution will continue;
otherwise, the next two commands in the command line or the macro will be skipped.

Related Commands: CF, CN, IF

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Command: aIPn -- Interrupt on Absolute Position 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command is used to determine when servo axis 'a' has achieved the specified position
'n' referenced by the home position (or zero). When that position has been reached, the "breakpoint
reached" flag in the status register will be set. This command can be issued before or after the
servo has been commanded to move.

Related Commands: IR, TB

Command: aIRn -- Interrupt on Relative Position 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command is used to determine when servo axis 'a' has achieved the specified position
'n' referenced by the current position when this command is executed. When that position has been
reached, the "breakpoint reached" flag in the status register will be set. This command can be
issued before or after the servo has been commanded to move.

Related Commands: IP, TB

Command: ISn -- If Bit 'n' of Accumulator is Set (1) --

Argument: 0 <= n <= 31

If bit 'n' of the accumulator is set (equals 1), command execution will continue; otherwise,
the next two commands in the command line the or the macro will be skipped.

Related Commands: IC

Command: IUn -- If Accumulator Unequal to 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

If the accumulator is unequal to the value 'n', command execution will continue; otherwise,
the next two commands in the command line or the macro will be skipped.

Related Commands: IE

Command: RPn -- Repeat --

Argument: 0 <= n <= 65,535

This command causes the command line to repeat 'n' more times. If 'n' is not specified or is
"0", the command line is repeated indefinitely.

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Command: WAn -- Wait ÔnÕ milliseconds --

Argument: 0 <= n <= 65,535

This command causes a wait period of 'n' milliseconds before going on to the next
command.

Command: aWEn -- Wait for Edge --

Argument: 0 or 1

This command waits until the Coarse Home Input Active bit in the status word of servo axis
'a' is at the logic state specified by 'n' before continuing command execution. If 'n' is not specified
or is 0, it will wait for the Home input to go inactive. If 'n' is 1, it will wait for the Home input to go
active.

Note: The argument for this command works in reverse as compared to that of the IMCSA
controller.

Related Commands: FE

Command: WFn -- Wait for I/O Channel "Off" --

Argument: 0 <= n <= 63
Default: "Off"

This command waits until I/O channel 'n' is in the "off" state before continuing command
execution.

Related Commands: CF, CN, WN

Command: aWI -- Wait for Index --

This command will wait for the occurrence of an Index input signal on servo axis 'a' before
continuing to the next command. If a Find Index (FI) command has not been issued prior to this
command, no waiting will occur.

Related Commands: CI, FI

Command: WNn -- Wait for I/O Channel "On" --

Argument: 0 <= n <= 63
Default: "Off"

This command waits until I/O channel 'n' is in the "on" state before continuing command
execution.

Related Commands: CF, CN, WF

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Command: aWPn -- Wait for Absolute Position 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command is used to determine when servo axis 'a' has achieved the specified position
'n' referenced by the home position (or zero). Until that position has been reached, command
execution will be suspended. This command can be issued before or after the servo has bee n
commanded to move; however, if the servo is not moving, then command execution may be
suspended indefinitely.

Related Commands: WR

Command: aWRn -- Wait for Relative Position 'n' --

Argument: -2,147,483,647 <= n <= 2,147,483,647

This command is used to determine when servo axis 'a' has achieved the specified position
'n' referenced by the current position when this command is executed. Until that position has been
reached, command execution will be suspended. This command can be issued before or after the
servo has been commanded to move; however, if the servo is not moving, then command
execution might be suspended indefinitely.

Related Commands: WP

Command: aWSn -- Wait for Stop --

Argument: 0 <= n <= 65535

This command will wait until servo axis 'a' has stopped moving for 'n' milliseconds before
continuing to the next command. So that there is only one delay period, in the case where 'n' is
specified as "0", the command will wait for all servo axis' to stop moving before the delay is
executed.

Related Commands: ST

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4.6 Learned Position Storage (LPS) Commands

The LAC-25 uses part of its nonvolatile RAM (NVRAM) to create a 256 item table for storing
positions. This table overlaps the last 256 registers of the register table.

The LPS table is normally accessed by three commands: Learn Position (LP), Learn Target
(LT) and Move to Position (MP). The purpose for the LPS table is to allow the user to store pre­determined positions for later use (such as in contouring) as the NVRAM will retain data even when
powered down. In other cases, this table can be built through calculations using the register
commands.

Command: aLPn -- Learn Current Position --

Argument: 0 <= n <= 255

This command causes the current position of servo axis 'a' (that position reported by the
Tell Position (TP) command) to be stored in location 'n' of the Learned Position Storage table. This
command is useful for "teaching" target positions to the LAC-25.

Related Commands: LT, MP

Command: aLTn -- Learn Target Position --

Argument: 0 <= n <= 255

This command causes the current target position of servo axis 'a' (that position reported by
the Tell Target (TT) command) to be stored in the location 'n' of the Learned Position Storage
table. This command is useful for setting up a table of target positions via a downloading
procedure.

Related Commands: LP, MP

Command: aMPn -- Move to Index Table Position 'n' --

Argument: 0 <= n <= 255

This command causes the position contained by the Learned Storage Position table
location 'n' to become the new target position. This command will not initiate a motion; therefore,
a Go (GO) command may be required.

Related Commands: LP, LT

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4.7 Macro Commands

Command instructions can be entered and executed immediately, but the LAC-25 also has
the capability of using commands to form other commands called "macros". These macros are
stored in the nonvolatile RAM (NVRAM) and can be executed automatically. Macros are created
by stringing together one or more commands (with arguments), separated by commas, and
indicating where they are to be stored. It should be noted that macros can use indirect as well as
direct arguments. The LAC-25 allows for the creation of 256 macros consisting of a total of nearly
2,300 command instructions. Macro calls via the Macro Call (MC) command or the interrupt
system, may be nested up to 25 calls deep.

An example of a macro might be...

>MD5,SV1000000,SA10000,MA25000,GO,WS100<CR>

Once this command line is entered, it will become the definition for macro 5. When macro
5 is used via the Macro Call (MC), Macro Sequence (MS) or Macro Jump (MJ) commands, the
commands contained within the macro will be executed automatically.

There are a few necessary restrictions when creating macros. When using the Macro Define
(MD) command, it must be placed first in the command line and it may be used only once. This
also implies that it cannot be used as part of a macro. The Reset Macro (RM) command is similar
in that it too cannot be used as part of a macro.

Another feature of the LAC-25 is the ability to automatically execute macro "0" on power­up or after a Reset (RT) command. If macro "0" is not defined, the user will receive the ">" prompt,
and the LAC-25 will wait for manual input.

Command: DVn -- Disable Interrupt Vector 'n' --

Argument: 0 <= n <= 31

This command disables interrupt vector 'n'. This prevents any possibility of an interrupt
being caused by that source.

Related Commands: EV, LV

Command: EVn -- Enable Interrupt Vector 'n' --

Argument: 0 <= n <= 31

This command enables interrupt vector 'n'. This allows the possibility of an interrupt being
caused by that source.

Related Commands: DV, LV

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Command: JPn -- Jump to Command, Absolute --

Argument: 0 <= n <= 31

This command causes execution of a macro to jump to the absolute command specified
by 'nÕ. Commands are numbered sequentially starting from 0. If 'n' is specified whereas the
command would attempt to jump past the end of the macro, command execution will resume as if
the macro had ended.

Related Commands: JR

Command: JRn -- Jump to Command, Relative --

Argument: 0 <= n <= 31

This command causes execution of a macro to jump to the command specified by 'n'
relative to the current command location. If 'n' is specified as zero, then this command will jump to
itself. If 'n' is specified such that the command would attempt to jump past the end of the macro,
command execution will resume as if the macro had ended. If 'n' is specified such that the
command would attempt to jump to a point before the beginning of the macro, an error will be
reported.

Related Commands: JP

Command: LVn -- Load Interrupt Vector 'n' --

Argument: 0 <= n <= 31

This command loads interrupt vector table entry 'n' with the contents of the low 8-bits of the
accumulator. The following program fragment will cause execution of macro "10" upon the
activation of digital input 0 (while a macro program is running).

MD1,AL10 ; Load accumulator with number for macro "10".
MD2,LV0 ; Load that number to interrupt vector 0.
MD3,EV0 ; Enable interrupt vector 0.

MD10,MG"Input 0 was just activated.",RC

When input 0 is activated, the line "Input 0 was just activated." will be displayed.

Related Commands: DV, EV

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Command: MCn -- Macro Call --

Argument: 0 <= n <= 255

This command allows a previously defined macro specified by 'n' to be called like a
subroutine. When this command is used, the current macro being executed is pushed to the macro
stack and execution of macro 'n' begins. If macro 'n' has not been defined, then an error will be
reported. After execution of the defined macro, command execution will continue immediately
after the Macro Call (MC) command. The Macro Call (MC) command can be used any place in a
macro. Macro calls may be nested up to 25 times; however, it is NOT advisable for a macro to call
itself.

Related Commands: RC, UM

Command: MDn -- Macro Definition --

Argument: 0 <= n <= 255

This command is used to define a new macro. Any duplication of numbers will simply result
in the loss of the previously defined macro using that number and the loss of the memory that it
used. The Macro Define (MD) command must be the first command in the command line or an
error will be reported.

Related Commands: RM, TM

Command: MJn -- Macro Jump --

Argument: 0 <= n <= 255

This command may be used to "Jump" to a previously defined macro command. Once the
LAC-25 begins executing the new macro, it has no record of how it got there. This means that any
commands that appear after the Macro Jump (MJ) command will not be executed. If there is no
macro defined by the number 'n', an error will be reported. Once the end of the macro is
encountered, macro execution stops (See the Macro Sequence (MS) command). The Macro Jump
command can be used any place in a command string or macro command. It is also acceptable
for
a macro to jump to itself.

Related Commands: MC, MS

Command: MSn -- Begin Macro Sequence --

Argument: 0 <= n <= 255

This command will cause macros to be executed sequentially beginning with macro 'n'
until an undefined macro or an End Program (EP) command is encountered. This command can
be used anywhere in a command string or macro command. If the Macro Jump (MJ) or Macro Call
(MC) commands are encountered, macro execution will still continue to execute sequentially.

Related Commands: MC, MJ

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Command: RC -- Return from Macro Call --

When executed, this command will cause immediate return to the calling macro (assuming
there was one).

Related Commands: MC, interrupts

Command: RMn -- Reset Macro(s) --

Argument: 0 <= n < 255

This command is used to delete one or more macros. If an argument is used, the macro
specified by 'n' will be deleted and the memory it used will be lost. If no argument is used, all
macros will be deleted, and all macro memory will be recovered. A Reset Macro command (RM)
should be used before entering or downloading a new set of macro commands.

Related Commands: MD

Command: TMn -- Tell Macros --

Argument: -2 <= n <= 255

The Tell Macro (TM) command will display the commands which make up any macros that
have been defined. If 'n' >= 0 and 'n' <= 255, then the macro specified by 'n' be displayed. If 'n' = ­1, then all the macros will be displayed preceded by the individual macro number. If 'n' =-2, then
all macros will be displayed and will be preceded by the letters "MD" and the individual macro
number. This is useful when downloading programs from the LAC-25 to a computer in that you
need not re-enter the Macro Define (MD) command and number at the beginning of each macro.

Related Commands: MD

Command: UMn -- Un-push Macro(s) --

Argument: 0 or 1

This command is used for controlling the macro subroutine call and return stack. If this
command is used with no argument or an argument of "0" then one macro will be removed from
the macro stack. If there is no macro to be removed then a MACRO_STACK_UNDERFLOW error
will be reported. If the argument is "1" then the macro stack will be completely reset. The UM
command is used in the event that a macro is paused due to a program interrupt and it is not
desirable to return to that macro, or under some circumstances, a program may need to completely
reset itself.

Related Commands: MC, interrupts

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4.8 Input / Output (I/O) Commands

The user is able to manipulate the LAC-25's I/O channels via the use of several commands.
These include setting or clearing outputs, reading inputs and altering the logic type of both.

Command: BIn -- Bulk Input from I/O Port 'n' --

Argument: 0 <= n <= 7

This command reads the value at the 8-bit digital input port and copies it to the low 8-bits
of the accumulator with the lower channel being the lowest bit in the accumulator. The unused
bits of the accumulator will be set to 0. The state of the inputs will be determined by the Channel
High (CH) and Channel Low (CL) commands and the inputs will have been debounced if the Input
Debounce (ID) command is in effect.

Related Commands: BO

Command: BOn -- Bulk Output to I/O Port 'n' --

Argument: 0 <= n <= 7

This command copies the low 8-bits of the accumulator to the digital output port. The state
of the outputs will be determined by the Channel High (CH) and Channel Low (CL) commands.
Unused bits in the accumulator are ignored.

Related Commands: BI

Command: CFn -- Turn I/O Channel 'n' "Off" --

Argument: 0 <= n <= 63
Default: "Off"

This command will cause I/O channel 'n' to assume the "off" state. The actual output state
will depend on whether the channel is set active "on" (CH command) or active "off" (CL command).

Related Commands: CH, CL, CN

Command: CHn -- Make I/O Channel 'n' Active High --

Argument: 0 <= n <= 63
Default: Active high or active "on"

This command causes I/O channel 'n' to assume an active "on" mode.

Related Commands: CL

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Command: CLn -- Make I/O Channel 'n' Active Low --

Argument: 0 <= n <= 63
Default: Active high or active "on"

This command causes I/O channel 'n' to assume an active "off" mode.

Related Commands: CH

Command: CNn -- Turn I/O Channel 'n' "On" --

Argument: 0 <= n <= 63
Default: "Off"

This command will cause I/O channel 'n' to assume the "on" state. The actual output state
will depend on whether the channel is set active "on" or active "off".

Related Commands: CF, CH, CL

Command: IDn -- Input Debounce 'n' milliseconds --

Argument: 0 <= n <= 7
Default: 0

This command determines the length of debounce time, if any, that is applied to the digital
inputs. The digital inputs are sampled once every millisecond. What this means is that an input
must remain in a given state for 'n' samples before it is considered valid. If the argument 'n' is "0",
then no input debouncing in performed. This debouncing applies to the following commands: BI,
DF, DN, IF, IN, WF, WN.

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4.9 Future Expansion Interface

For future expansion, the LAC-25 provides a proprietary high speed serial data bus. Such
uses might include various external devices such as thumb-wheel switches, LED or LCD displays,
switch panels and additional number or types of input and output. This provides custom expansion
flexibility in certain qualified OEM applications.

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4.10 Serial Communications and Miscellaneous Commands

These commands control operation of the serial communication's interface and cover the
balance of the LAC-25 functions not fitting in the other categories.

Command: BK -- Break --

This command will cause the rest of the command line or macro to be skipped. This
command is used along with the Sequence Commands for conditional command execution.

Command: BRn -- Set Baud Rate --

Argument: 300, 600, 1200, 2400, 4800, 9600 or 19,200
Default: 9600

This command allows the user to change the baud rate at which the serial
communication's interface operates. Once this command has been issued with a valid argument,
the communication's interface will then immediately operate at the specified baud rate. This baud
rate will remain in place, even after power cycling the unit, until it is changed again. Please note

that the default baud rate is 9600.

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Command: CDn -- Capture Data --

Argument: 0 <= n <= 16383

This command allows for the capture and recording of data from an internal variable with
the user being able to later download and plot this data for analysis. The number of samples that
can be recorded depends on the amount of macro memory available at the time that the Capture
Storage (CS) command is issued.

The argument determines the number of samples to record. If an argument is used that is
greater than the allocated storage space, then the argument will be truncated to fit that space. Al l
data sizes are extended to 32 bits before they are stored.

Before using the CD command, a few things must be taken care of. The first of these is to
define an area to store the data. The Capture Storage (CS) command is used for this in that i t
allocates a storage area in the macro memory to where the data can be recorded. The next thing
to do is to specify the location and size of the data to be recorded. The internal 16-bit variable
ÒRecAddrÓ (see Register commands) is used to specify the location (or address) of the variable to be
recorded. The internal 16-bit variable ÒRecSizeÓ is used to specify the data size. If bit 0 of
ÒRecSizeÓ is equal to Ò1Ó then 8 bit data samples are recorded. If bit 1 of ÒRecSizeÓ is equal to Ò1Ó
then 16 bit data samples are recorded. If bits 0 and 1 of ÒRecSizeÓ are both Ò0Ó then 32 data
samples are recorded. The last thing that needs to be specified is the sample rate at which the data
is captured. This is set by writing the appropriate value to the 16-bit variable ÒRecRateÓ. T he
sample rate will be whatever the servo sample rate is (see SS command) divided by ÒRecRateÓ.

After using the CD command, the Dump Data (DD) command can be used to display the
data that was captured.

Example:

To make 2000 records of the actual position of axis 2 you would issue the following
commands:

CS2000 ; Reserve space for 2000 samples.
;
;
;
AL4,WW422 ; Servo rate = 1mS so Data rate = 4mS.
AL638,WW424 ; Set address of axis 2 Curp.
AL0,WW426 ; Set for 32-bit variable size.

The CS command should be used only once. After that, the CD and DD commands can b e
used repeatedly.

Related Commands: CS, DD

RecSize Recorded Variable Size

1 8 Bits
2 16 Bits
0 32 Bits

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Command: CSn -- Capture Storage --

Argument: 0 <= n <= 16383

This command is used to allocate storage space for the data recorder commands. The
argument determines the maximum number of samples that can be recorded. If an argument is
used that is greater than the macro memory available, then an error will be reported. Because
information pertaining to this command is stored in non-volatile memory, once this command is
issued, the storage space will remain, even after power-cycling. To recover the macro memory
used by this command, use the Reset Macros (RM) command.

Related Commands: CD, DD

Command: DDn -- Dump Data --

Argument: 0 <= n <= 16383

This command is used to dump data that has been previously recorded by the Capture Data
(CD) command to the display. The argument determines the number of recorded samples to
display. If an argument is used that is greater than the allocated storage space, then the argument
will be truncated to fit that space.

Related Commands: CD, CS

Command: DM -- Decimal Mode --

Default: Decimal Mode

This command causes all numerical input and output to be interpreted as decimal or base

10. Numbers will be output with a leading "-" if they are less than zero.

Related Commands: HM

Command: EF -- Echo Off --

Default: Echo On

This command suppresses the echoing of characters received by the serial
communication's interface. It is normally used in the half-duplex mode of operation in serial
communications.

Related Commands: EN

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Command: EN -- Echo On --

Default: Echo On

This command causes characters received from the serial communication's interface to be
echoed as they are received. It is normally used in the full-duplex mode of operation in serial
communications.

Related Commands: EF

Command: GAn -- Get A/D Channel

Argument: 0 <= n <= 9

This command will cause a conversion on A/D channel 'n' and will store the result in the
bottom 10 bits of the accumulator. Unused bits will be set to 0.

Related Commands: TA

Command: HF -- Hardware Handshaking Off --

Default: Hardware handshake off

This command does not function and is retained for backward compatibility reasons.

Command: HM -- Hexadecimal Mode --

Default: Decimal Mode

This command causes all numerical input and output to be interpreted as hexadecimal or
base 16. Numbers will be output as 2, 4 or 8 digits with leading 0's if they are positive and leading
F's if they are negative.

Related Commands: DM

Command: HN -- Hardware Handshaking On --

Default: Hardware handshake off

This command does not function and is retained for backward compatibility purposes.

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Command: MG[[""][:n][:N]] -- Display Message --

Argument: 0 <= n <= 511

This command allows for the display of an optional text string and / or an optional register
variable with the additional option of inhibiting the carriage return / linefeed (CRLF) at the end.

The text string must be enclosed by quotes """ and may be up to 127 characters long.
Additional parameters must be separated by a colon ":" .

The following are all the valid examples. Note that the "N" option inhibits a CRLF.
Parameters must be given in specific order.

>MG ; Display CRLF only.

>MG"THE BLACK BEAR IS " ; Display "THE BLACK BEAR IS " followed by

; CRLF.

>MG0 ; Display contents of register 0 followed

; by CRLF.

>MGN ; This command displays nothing followed

; by nothing.

>MG"THE BLACK BEAR IS ":0 ; Display "THE BLACK BEAR IS " followed by

; the contents of register 0 followed by

; CRLF.

>MG"THE BLACK BEAR IS ":N ; Display "THE BLACK BEAR IS " followed by

; nothing.

>MG0:N ; Display the contents of register 0

; followed by nothing.

>MG"THE BLACK BEAR IS ":0:N ; Display "THE BLACK BEAR IS " followed by

; the contents of register 0 followed by

; nothing.

Command: NO -- No Operation --

This command does nothing. It can be used to cause short delays in command line
executions or to fill out commands (see Sequence Commands).

Command: RT -- Reset --

This command performs a complete restart of the LAC-25, including restoration of a ll
default conditions, such as acceleration and velocity, and leaves all servo axis' in the "off" state.

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Command: VI[[""][:n][:N]] -- Variable Input --

Argument: 0 <= n <= 255

This command allows for the display of an optional text string, an optional carriage return /
linefeed (CRLF) and the entry of integer numeric operator input to a register variable.

The text string must be enclosed by quotes """ and may be up to 127 characters long.
Additional parameters must be separated by a colon ":". Entered numbers will be interpreted (as
decimal or hexadecimal) as determined by the current mode set by the DM or HM commands. If
the value entered by the operator is in error (indeterminate), then the Bad Input bit (bit 15 of the
variable SYSSTAT) is set, otherwise it is cleared. If no operator input is entered (only a carriage
return is received), then no register will be altered. If no argument is given and operator input is
received,
then register 0 will be the default recipient of the input value.

The following are all the valid examples. Note that the "N" option causes a CRLF.
Parameters must be given in specific order.

>VI ; Wait for operator input (if any) to register 0.

>VI"ENTER NUMBER: " ; Display "ENTER NUMBER: " and wait for

; operator input (if any) to register 0.

>VI5 ; Wait for operator input (if any) to

; register 5.

>VIN ; Display a CRLF and wait for operator input

; (if any) to register 0.

>VI"ENTER NUMBER: ":5 ; Display "ENTER NUMBER: " and wait for

; operator input (if any) to register 5.

>VI"ENTER NUMBER: ":N ; Display "ENTER NUMBER: " followed by a

; CRLF and wait for operator input (if any)
; to register 0.

>VI5:N ; Display a CRLF and wait for operator input

; (if any) to register 5.

>VI"ENTER NUMBER: ":5:N ; Display "ENTER NUMBER: " followed by a CRLF

; and wait for operator input (if any) to
; register 5.

Command: XFn -- Set XOFF Code --

Argument: 0 <= n <= 255
Default: 19

This command does not function and is retained for backward compatibility purposes.

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Command: XNn -- Set XON Code --

Argument: 0 <= n <= 255
Default: 17

This command does not function and is retained for backward compatibility purposes.

Command: ZF -- Format NVRAM --

Argument: n = 123

This command re-formats and re-initializes the LAC-25's non-volatile static ram (NVRAM).
This means that any macros will be deleted and their space recovered, register contents will be set
to 0 and the baud rate (among other things) will be set to their default values. Evidence of the baud
rate change will not be immediate but will occur when the unit is either power cycled or the Reset
(RT) command is issued. This command is intended for use by the manufacturer to place the unit
in a known state after testing but is sometimes useful as a "when all else fails" means under certain
circumstances. This command must include an argument "key code" of "123" in order to function.
This is to reduce the possibility of accidental execution.

Command: ZZ -- Dump Memory --

Argument: 0 <= n <= $3FFFF

This command does a display dump of the memory starting at address 'n'. This command is
intended for use by the manufacturer for diagnosing purposes.

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5. Appendix A, LAC-25 Error Code Definitions

1 - ARGUMENT ERROR.

This error indicates that a command argument was not given or was specified out of the
permissible numerical range.

2 - INVALID COMMAND.

This error indicates that an invalid or unrecognized command was specified in the
command line.

3 - INVALID MACRO COMMAND.

This error indicates that an invalid or unrecognized command was used in defining a
macro.

4 - MACRO ARGUMENT ERROR.

This error indicates that a command argument was not given or was specified out of the
permissible numerical range in defining a macro.

5 - MACRO NOT DEFINED

This error indicates that execution of an undefined macro was attempted.

6 - MACRO OUT OF RANGE.

The LAC-25 allows for a maximum of 256 macros (numbered 0 to 255). This error indicates
that an attempt was made to access a macro out of this boundary.

7 - OUT OF MACRO SPACE.

The LAC-25 allows for a maximum of 256 macros with up to 256 commands per macro and
approximately 15800 bytes of macro storage space. Each macro command requires 6 bytes of
macro storage memory and each macro requires an overhead of 1 byte. This error indicates that so
many macros/macro commands have been defined that there is no remaining memory to define
more.

8 - CAN'T DEFINE MACRO IN A MACRO.

This error indicates that an attempt was made to define a macro from another macro that is
currently being executed. This is not allowed on the LAC-25 as to prevent loss of program control
due to possible "nesting".

9 - CAN'T DEFINE MACRO WHILE SERVO ENABLED.

This error indicates that attempt was made to define a macro while a servo axis the was
enabled (i.e.: "MN"). This is not allowed on the LAC-25 as to prevent loss of program and/or servo
control due to macro memory space definition contention.

10 - MACRO JUMP ERROR.

This command indicates that an attempt was made to jump ("MJ" command) to a
command within a macro that does not exist.

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11 - OUT OF MACRO STACK SPACE.

When a macro is called by another macro (via the "MC" command or a macro interrupt),
the return macro and macro command number must be saved along with other internal variables.
This error indicates that
the memory space set aside for this purpose has been exhausted and no more "calls" may be
attempted. The LAC-25 is capable of macro calls nested 25 deep.

12 - MACRO MUST BE FIRST COMMAND.

When defining a macro, the "MD" command must be the first command in the command
line. This error indicates that this requirement was not met.

13 - STRING ERROR

When using a MG or VI command, no closing quote was encountered.

14 - MACRO STRING ERROR

When using a MG or VI command in defining a macro, no closing quote was encountered.

15 - SYNTAX ERROR

Indicates the improper usage of the MG or VI commands.

16 - MACRO SYNTAX ERROR

Indicates the improper usage of the MG or VI commands while defining a macro.

17 - AXIS RANGE ERROR

The axis specified is out the possible numerical range.

18 - INTERRUPT MACRO NOT DEFINED

During the course of interrupt processing, at attempt was made to go to an undefined
macro.

19 - INTERRUPT MACRO STACK ERROR

Indicates that the macro stack has run out of space during interrupt processing.

20 - MACRO STACK OVERFLOW

The macro stack has run out of space.

21 - MACRO STACK UNDERFLOW

An attempt was made to "pop" a macro off of the macro stack when there was no macro to
pop.

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6. Appendix B, Summary of LAC-25 Commands

Parameter Commands

DB - - Set Dead Band
FA -- Feed-forward, Acceleration
FF - - Fail Input Off
FN - - Fail Input On
FR - - Derivative Sampling Frequency
FV -- Feed-forward, Velocity
GR -- Set Electronic Gearing Ratio
IL -- Integration Limit
LF -- Limit Off
LM -- Limit Mode
LN -- Limit On
OM - - Output Mode
OO -- Output Offset
PH - - Phase
RI - - Sampling Rate of Integral
SA - - Set Acceleration
SC - - Set Current Gain
SD -- Set Derivative Gain
SG - - Set Proportional Gain
SI -- Set Integral Gain
SQ - - Set Torque
SS -- Set Servo Speed
SV - - Set Velocity

Reporting Commands

TA -- Tell A/D Channel
TB -- Tell Breakpoint
TC - - Tell Channel
TD - - Tell Derivative Gain
TE -- Tell Last Command Error
TF - - Tell Following Error
TG -- Tell Position Gain
TI - - Tell Integral Gain
TK -- Tell (K)Constants
TL -- Tell Integration Limit
TM -- Tell Macros
TO -- Tell Optimal Position
TP -- Tell Real Position
TQ -- Tell Torque
TR - - Tell Register
TS -- Tell Status
TT - - Tell Target Position
TV -- Tell Current Velocity
VE - - Tell Version

Motion Commands

AB - - Abort Motion
CI - - Capture Index
DA -- Disable Axis
DH - - Define Home
DI - - Set Direction
EA - - Enable Axis
EG - - Enter Electronic Gearing Mode
FE -- Find Edge (Home)

FI - - Find Edge (Index)
GH -- Go Home
GO - - Go (start motion)
MA - - Move Absolute
MF - - Motor Off
MN -- Motor On
MR -- Move Relative
PM -- Position Mode
QM - - Torque Mode
SE - - Set Maximum Following Error
ST - - Stop Motion
VM -- Velocity Mode

Sequence Commands

DF - - Do if Channel "Off"
DN - - Do if Channel "On"
EP - - End Program
IB -- If Accumulator Below
IC -- If Accumulator Bit is Clear
IE -- If Accumulator Equal to 'n'
IF - - If Channel "Off"
IG -- If Accumulator is ">" 'n'
IN - - If Channel is "On"
IP -- Interrupt on Absolute Position
IR - - Interrupt on Relative Position
IS - - If Accumulator Bit is Set
IU - - If Accumulator Unequal to 'n'
RP - - Repeat
WA - - Wait
WE -- Wait for Edge (Home or Index)
WF -- Wait for Channel "Off"
WI - - Wait for Index
WN -- Wait for Channel "On"
WP -- Wait for Absolute Position
WR - - Wait for Relative Position
WS -- Wait for Stop

Learned Position Storage Commands

LP - - Learn Current Position
LT - - Learn Target Position
MP -- Move to Position

Macro Commands

DV -- Disable Interrupt Vector
EV - - Enable Interrupt Vector
JP - - Jump Absolute
JR - - Jump Relative
LV -- Load Interrupt Vector
MC -- Macro Call
MD - - Macro Definition
MJ - - Macro Jump
MS - - Macro Sequence
RC -- Return from Call
RM - - Reset Macro(s)
TM -- Tell Macro(s)

UM -- Unpush Macro

Serial Comm. and Misc. Commands

BK - - Break
BR - - Baud Rate
CD -- Capture Data
CS -- Capture Storage
DD -- Dump Data
DM - - Decimal Mode
EF - - Echo Off
EN - - Echo On
GA - - Get A/D Channel
HF - - Hardware Handshaking Off
HM -- Hexadecimal Mode
HN - - Hardware Handshaking On
MG -- Display Message
NO - - No Operation
RT - - Reset
VI -- Variable Input
XF - - Set XOFF Code
XN - - Set XON Code
ZF -- Format NVRAM
ZZ - - Dump Memory

Register Commands

AA - - Accumulator Add
AC -- Accumulator Complement
AD -- Accumulator Divide
AE - - Accumulator Exclusive-Or
AL - - Accumulator Load
AM -- Accumulator Multiply
AN - - Accumulator And
AO - - Accumulator Or
AR -- Copy Accumulator to Reg.
AS - - Accumulator Subtracted
RA -- Copy Register to Accum.
RB - - Read Byte
RL - - Read Long
RW -- Read Word
SL - - Accumulator Shift Left
SR -- Accumulator Shift Right
TR - - Tell Register
WB -- Write Byte
WL -- Write Long
WW -- Write Word

Input / Output (I/O) Commands

BI -- Bulk I/O Input
BO - - Bulk I/O Output
CF - - Turn Channel "Off" -­CH - - Make Channel Active "On"
CL -- Make Channel Active "Off"
CN - - Turn Channel "On"
ID - - Input Debounce Delay

74

SMAC LAC-25 Technical Reference Manual

7. Appendix C, LAC-25 Connector Pin Definitions

POWER

11

RS-232

J1 - Power Interface
8-Pin 5.08mm Centers Phoenix
Digi-Key# ED1721-ND

1. Axis 1 Motor- output

2. Axis 1 Motor+ output

3. Axis 2 Motor- output

4. Axis 2 Motor+ output

5. Main V+ power input

6. Main power return

J2 - Axis Interface
26-Pin High density female D-Sub
NorComp# HDT26P : Digi-Key# T815M-ND

1. Axis 2 Limit- input

2. Axis 1 Fault input

3. Axis 1 Limit+ input

4. +5 VDC

5. +5 VDC

6. Axis 2 Encoder phase B-

7. Axis 2 Encoder phase B+

8. Axis 1 Encoder phase B-

9. Axis 1 Encoder phase B+

10. Axis 2 Fault input

11. Axis 2 Limit+ Input

12. Axis 1 Home Input

13. Common

14. Common

15. Axis 2 Encoder phase A-

16. Axis 2 Encoder phase A+

17. Axis 1 Encoder phase A-

18. Axis 1 Encoder phase A+

19. Axis 2 Home Input

20. Axis 1 Limit- Input

21. Common

22. Common

23. Axis 2 Encoder Index-

24. Axis 2 Encoder Index+

25. Axis 1 Encoder Index-

26. Axis 1 Encoder Index+

J3 - Optional I/O Expansion Interface
6-Pin Modular Type
AMP# 5-641337-3 : Digi-Key# A9093-ND

1. Receive Data- input

I/O EXP USER I/O SERVO INTERFACE POWER INTERFACE

STATUS

1

2. Transmit Data- output

3. Receive Data+ input

4. Transmit Data+ output

5. Clock+ output

6. Clock- output

J4 - RS-232 Communication Interface
6-Pin Modular Type
AMP# 5-641337-3 : Digi-Key# A9093-ND

1. Handshake output

2. Handshake input

3. Receive data input

4. Transmit data output

5. Common

6. +5 VDC

J5 - User I/O Interface
26-Pin High density female D-Sub
NorComp# HDT26P : Digi-Key# T815M-ND

1. Axis 2 Analog output

2. Analog input 2

3. Analog input 1

4. Opto-output 3

5. Opto-output 3 return

6. Opto-input 1

7. Opto-input 1 return

8. Opto-output 1

9. Opto-output 1 return

10. Axis 1 Analog output

11. Axis 2 Analog output return

12. Analog input 0

13. Opto-input 3

14. Opto-input 3 return

15. Opto-output 2

16. Opto-output 2 return

17. Opto-input 0

18. Opto-input 0 return

19. Axis 1 Analog output return

20. 10 VDC Analog refence output.

21. Analog reference return

22. Common

23. Opto-input 2

24. Opto-input 2 return

25. Opto-output 0

26. Opto-output 0 return

1

1

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SMAC LAC-25 Technical Reference Manual

8. Index

A

A/D interface ¥ 11
Accumulator ¥ 44
Appendix A

Error Code Definitions ¥ 72

Appendix B

Summary of Commands ¥ 74

Appendix C

Connector Pin Definitions ¥

75
Axis Variable Descriptions ¥ 45
Axis Variable Locations ¥ 47

C

Command

AA ¥ 48
AB ¥ 37
AC ¥ 48
AD ¥ 48
AE ¥ 49
AL ¥ 49
AM ¥ 49
AN ¥ 49
AO ¥ 49
AR ¥ 49
AS ¥ 49
BI ¥ 62
BK ¥ 65
BO ¥ 62
BR ¥ 65
CD ¥ 66
CF ¥ 62
CH ¥ 62
CI ¥ 38
CL ¥ 63
CN ¥ 63
CS ¥ 67
DA ¥ 38
DB ¥ 19
DD ¥ 67
DF ¥ 52
DH ¥ 38
DI ¥ 38
DM ¥ 67
DN ¥ 52
DV ¥ 58
EA ¥ 39
EF ¥ 67
EG ¥ 39
EN ¥ 68
EP ¥ 52
EV ¥ 58
FE ¥ 39
FF ¥ 20
FI ¥ 40
FN ¥ 20
FR ¥ 20
FV ¥ 19, 21

GA ¥ 68
GH ¥ 40
GO ¥ 40
GR ¥ 21
HF ¥ 68
HM ¥ 68
HN ¥ 68
IB ¥ 52, 53
ID ¥ 63
IE ¥ 53
IF ¥ 53
IG ¥ 53
IL ¥ 22
IN ¥ 53
IP ¥ 54
IR ¥ 54
IS ¥ 54
IU ¥ 54
JP ¥ 59
JR ¥ 59
LF ¥ 22
LM ¥ 22
LN ¥ 23
LP ¥ 57
LT ¥ 57
LV ¥ 59
MA ¥ 40
MC ¥ 60
MD ¥ 60
MF ¥ 40
MG ¥ 69
MJ ¥ 60
MN ¥ 41
MP ¥ 57
MR ¥ 41
MS ¥ 60
NO ¥ 69
OM ¥ 23
OO ¥ 24
PH ¥ 24
PM ¥ 41
QM ¥ 42
RA ¥ 50
RB ¥ 50
RC ¥ 61
RI ¥ 25
RL ¥ 50
RM ¥ 61
RP ¥ 54
RT ¥ 69
RW ¥ 50
SA ¥ 25
SC ¥ 26
SD ¥ 26
SE ¥ 42
SG ¥ 26
SI ¥ 26
SL ¥ 50
SQ ¥ 27
SR ¥ 51
SS ¥ 28
ST ¥ 42

SV ¥ 29
TA ¥ 30
TB ¥ 30
TC ¥ 30
TD ¥ 31
TE ¥ 31
TF ¥ 31
TG ¥ 31
TI ¥ 31
TK ¥ 32
TL ¥ 33
TM ¥ 33, 61
TO ¥ 33
TP ¥ 33
TQ ¥ 33
TR ¥ 33, 51
TS ¥ 34
TT ¥ 35
TV ¥ 35
UM ¥ 61
VE ¥ 36
VI ¥ 70
VM ¥ 43
WA ¥ 55
WB ¥ 51
WE ¥ 55
WF ¥ 55
WI ¥ 55
WL ¥ 51
WN ¥ 55
WP ¥ 56
WR ¥ 56
WS ¥ 56
WW ¥ 51
XF ¥ 70
XN ¥ 71
ZF ¥ 71
ZZ ¥ 71

Command summary ¥ 74

D

Dedicated digital inputs ¥ 8
Digital I/O "states" ¥ 9
Digital I/O interface ¥ 8
Downloading commands ¥ 18

E

Electronic Gearing Mode ¥ 37
Enabling and disabling

interrupts ¥ 13
Encoder interface ¥ 11
Entering commands ¥ 17
External fault input ¥ 8

F

Fault condition ¥ 8

76

SMAC LAC-25 Technical Reference Manual

G

Gear Ratio ¥ 37
General purpose inputs ¥ 8
General purpose outputs ¥ 9

I

I/O Commands ¥ 62
I/O Expansion interface ¥ 64
I/O technical specifications ¥ 10
Indirect Argument ¥ 44
Internal variables ¥ 44
Interrupt completion ¥ 15
Interrupt latency ¥ 15
Interrupt priority ¥ 14
Interrupt Sources ¥ 13, 14
Interrupt vector table ¥ 13
Introduction ¥ 7
Invalid Command ¥ 17

L

Learned Position Storage

Commands ¥ 57

Loading Vector Table ¥ 13

M

Macro "0" ¥ 58
Macro commands ¥ 58
Macro interrupt system ¥ 13

Mathematical Operations ¥ 44
Miscellaneous commands ¥ 65
Motion commands ¥ 37

O

Output driver interface ¥ 11
Over-temperature Sensor ¥ 11

P

Parameter commands ¥ 19

R

Register commands ¥ 44
Register Space ¥ 44
Reporting commands ¥ 30

S

Sequence Commands ¥ 52
Serial communications

commands ¥ 65
Serial interface ¥ 11
Specifications ¥ 7
Status Bits

Accelerating ¥ 34

Bad Input ¥ 34

Breakpoint Reached ¥ 34

Coarse Home Input Active ¥

34

Current Direction ¥ 34
Current Mode ¥ 35
Desired Direction ¥ 34
Fail Input Flag ¥ 34
Limit- Active ¥ 35
Limit- Enabled ¥ 35
Limit Mode Abort ¥ 35
Limit Mode Stop ¥ 35
Limit- Tripped ¥ 35
Limit+ Active ¥ 35
Limit+ Enabled ¥ 35
Limit+ Tripped ¥ 35
Looking for Edge ¥ 34
Looking for index ¥ 34
Over Temperature / Fault ¥

34
Position Mode ¥ 34
Servo Enabled ¥ 34
Servo Error ¥ 34
Servo Stopping ¥ 34
Torque Mode ¥ 34
Trajectory Complete ¥ 34
Velocity Mode ¥ 34

Status LED ¥ 17
Switching Frequency ¥ 11
System Variable Descriptions ¥

46

System Variable Locations ¥ 48

T

Table of Contents ¥ 5
Trapezoidal Velocity Profile ¥ 37

77