PMC LN3X Series User manual

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LN3X Series Motor and Drives
Operator's Manual
PN 04-01920 C
PRECISION MOTION CONTROLS
2175 De La Cruz Blvd., #1
Santa Clara, CA 95050

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Contents
INTRODUCTION...................................................................................................................................................... 3
Description............................................................................................................................................................. 3
Features ................................................................................................................................................................. 3
Warranty................................................................................................................................................................ 3
INSTALLATION........................................................................................................................................................ 5
Unpacking .............................................................................................................................................................. 5
Cooling ................................................................................................................................................................... 5
Wiring .................................................................................................................................................................... 5
Commands ........................................................................................................................................................... 10
Electrical .............................................................................................................................................................. 15
Motor Compatibility............................................................................................................................................. 15
Indexer Inputs ...................................................................................................................................................... 15
Resonances .......................................................................................................................................................... 15
Appendix
LN3X Specification

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INTRODUCTION
Description
The LN3X Drive is a microstepping drive with a linear amplifier output stage. It is intended for
stepping motor applications where motor vibration must be minimized and EMI noise can't be tolerated. The
LN3X drive eliminates EMI noise in the steady state condition and minimizes EMI noise while running. The
drive’s dual voltage supply design allows this unit to have speed vs torque curves superior to most
pulsewidth modulated drives while minimizing the stress on the power amplifier. The drive provides
extremely smooth movement with a microstepping resolution of 25600 steps/revolution; this makes this
product suitable involving in applications with precision equipment where vibration must be minimized.
The LN3X drive can be purchased with a wide range of motors with torque ranges between 60 and 600 in-
oz. The drive has two dip switches for easy access to current selection, auto-shutdown, 3rd harmonic
correction, and a test mode. Each function is described in detail further on in the manual.
A standard 25 pin D connector with TX, RX Gnd, limit inputs, Home input and Fault output make this drive
easy to interface with existing terminals on the market.
LN3X can be ordered in 2.5 amp or 3.5 amp peak current version. For 3.5 amp, the motor will go to standby
mode automatically after the motor stops for 2 seconds. The voltage of the motor is limited to the low
voltage supply. The high current version is intended for the applications that require high torque and low
speed applications. Caution should be used when configuring current setting. The motor can be damaged if
too much current beyond its specification is forced through the windings.
There is a 2k Internal EEPROM that can be used to store a move sequence after power up.
Features
The LN3X is a high performance linear microstepping drive designed for low noise applications. The
systems dual supply allows cool operation at idle and low speed operation while still enabling the drive to
obtain high speeds.
* Wave shape correction of 3%, 5% third harmonic distortion
* 115/220 VAC line voltage operation
* Auto-standby reduces motor current to 50% after 2 seconds if no input is received.
* Short circuit current protection
* Low voltage sense
* Current configurable through dip switches
* External fault indicators
Warranty

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PMC's linear drives have a one year warranty against manufacturing defects from the date of purchase. If
your unit should ever fail, and you wish to send it back for repairs; you should do the following:
1. Get the serial number from the defective unit.
2. Check purchase date to see if the unit is under warranty. If not, obtain a purchase order number
for repair costs.
3. Call Precision Motion Controls or email to [e-mail] for a return authorization
4. Ship to:
Precision Motion Controls
5339 Prospect Rd. #209
San Jose, CA. 95129
Attention RMA #_____________

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INSTALLATION
Unpacking
When unpacking your unit verify that the unit was not damaged during shipping. Report any damage found
to the shipper. Check the box contents against the packing slip. The box will contain the driver, an AC line
cord and manual. If a complete system was bought a motor will also be included.
Connect the motor to the driver, check that the AC switch selection is set to the proper voltage and set the
motor current, then plug in the AC line cord. Ensure the shaft of the motor is producing torque. If you are
able to rotate the motor shaft, the motor is not producing torque. Check if the fault LED is on; and unplug the
AC line cord. Check for any loose motor wires or a blown fuse. Contact the factory for a return authorization
if the above checks prove negative. IF the above test works turn off the drive and put the unit into the test
mode by placing dip-switch 2 position 7 to the on position. Plug the AC cord in; the motor will rotate 0.7
rev/second.
CAUTION, always disconnect the AC power prior to connecting or disconnecting the motor to the drive.
Mounting
The LN3X Drive comes with built in mounting brackets to facilitate mounting. The unit may be mounted in
any direction. Our built-in fan eliminates the need for the user to be concerned about cooling. It is
recommended that 3 inches be allowed around the box for air flow into the system. See appendix for a
detailed drawing of the driver dimensions.
Cooling
The drive has a fan cooled enclosure; the surrounding temperature of the environment should not exceed 40
degrees centigrade. If the driver needs to be in a warmer environment, consult the factory for
recommendations.
Wiring
Motor Connections
The drive has three connectors on the box; a standard AC inlet, a 25 pin "D" connector for the indexer, and
a 5 pin Phoenix connector for the motor.
If a motor is purchased with the drive, the motor will have the connector attached to it; otherwise a connector
with screw mountings will be supplied. The center pin of the connector is for the shield connection of the
motor cable. The center pin (shield) is connected to the motor case on PMC supplied motors. The motor
connections are listed below.
Phoenix 5 pin connector
A+ (Red)
A- (Black)
Shield (Earth Ground)
B+ (White)

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B- (Green)
You can change motor rotation direction by swapping A+ with A- or B+ with B-.
Line Power
The drive has an AC line voltage (115 or 220 VAC) selection switch on the side of the unit. All units are
shipped with the selection switch in the 115 VAC line voltage position. The correct line cord is supplied for
connection of 115 VAC power. Make sure that the unit is plugged into a wall socket with earth ground.
It is very important to select the line voltage correctly before turning on the drive.
Indexer Connections
The drive has RS232 compatible signals for TX, RX and Communications ground. Inputs for limit CW, CCW
and home are provided; these signals are photo-coupled to eliminate ground loops.
The RS232 serial communication uses 3 pin standard RS232C interface, the setup is listed in the following
table.
BAUD RATE DATA BITS PARITY STOP BITS
9600 8 NONE 1
If an over-current, under-voltage or over-temperature condition is detected the photo-transistor across the
Fault+ and Fault- output is turned on. If the Fault signal is active, the drive's AC power needs to be cycled to
reactivate the drive.
The Error condition is satisfied if the drive current exceeds 7 Amps, line voltage drops below 90 VAC, or if
the internal temperature exceeds 50 degree C.
25 pin "D" connector
1 Limit + Pwr
14 Limit + ret
2 Limit - Pwr
15 Limit - ret
16 Home Pwr
17 Home ret
9 Fault + (collector)
21 Fault - (emitter)
11 RXD
24 TXD
12 RS232 ret

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Typical inputs, output connections
The limits and home typically are connected to 5V TTL signal, they are active when there is a 5V drop
across + and –pins. A current limit resistor is required between the Fault+ and external 5V supply. Typically
a 10K resistor is used for 5V supply. The maximum voltage between Fault+ and Fault- is 50V.
Switch Settings
Disconnect AC power from the unit prior to attempting to change any switch settings. The switch settings
control the maximum winding current, 3rd harmonic correction, and test mode.
The two dip switches are accessible from the bottom of the box. The following graphic shows the location of
2 switches. Switch1 (SW1) is the on the left hand side in the graphic.
Figure 1: Dip Switch location SW1 on the left, SW2 on the right.
The tables below list the dip switch settings for various motor currents, motor waveform and various RS232
communication options.

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TABLE 1
Switch 2 1 2 3 4 5 6 7 8
PMC - 60 MTR on on off off off off X X
PMC - 90 MTR on on off off off off X X
PMC - 130 MTR off off off off off off X X
PMC - 160 MTR on off off off off off X X
PMC - 260 MTR on off off off off off X X
PMC - 320 MTR on off off off off off X X
PMC - 420 MTR on off off off off off X X
PMC - 600 MTR on on on off off off X X
Test Mode X X X X X X on X
Standby X X X X X X X off
The first 6 switches of dip switch 2 are the current settings and are approximately 40 ma per bit for 2.5 amp
drivers and 56ma per bits for a 3.5amp driver. The off position of the switch selects the current; switch 6 is
the most significant bit. The PMC supplied motors run at approximately 2.5 amp/phase peak current. The
motor current table above is for 2.5 amp version. In the 2.5amp version the user can activate the standby
mode by selecting switch 2-8 to off position. Standby mode is automatically entered in the 3.5 amp model
regardless of the switch setting
Test
This is a mode that is entered upon power up if switch 2-7 is in the on position. The motor will rotate
at 0.7 rev/sec after power up. Power must be turned off and switch 2-7 put in the off position to leave test
mode.
The commands are ignored in test mode. Set Test mode to the off position before entering command mode.
Auto-Standby
The motor current is reduced to 50% after 2 seconds of no movement in the 2.5 amp version when
switch 2-8 is selected OFF position. The motor current goes to standby mode regardless of the switch
setting in the 3.5 amp version.
Switch 1
1 2 3 4 5 6 7 8
wave shape
0% X X X on on on X X
+3% X X X off on on X X
-3% X X X on off on X X
5% X X X off off on X X
-5% X X X on on off X X
enable DN on X X X X X X X

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enable echo X on X X X X X X
enable CR X X off X X X X X
The user has the ability to select the motor current wave shape. This will help provide even steps
and minimize motor vibrations for various motors. If you use motors that have a large detent torque
compared to the motor torque you may need to select a wave form other than 0% wave shape. The wave
shape corrections are based on a percentage of third harmonic distortion.
Switch 1-1 enables and disables the characters from being echoed from the drive. It is best to have
the echo enabled while debugging.
Switch 1-2 enables or disables the drive from sending a DN response when a move stops. This can
be used as an indication that the drive has reached the desired position without polling the position status.
Switch 1-3 can be set to output a "CR" carriage return after status
Switches 7 and 8 set the system ID so that the units can be daisy chained.
Fault indicators
There are two LED indicators adjacent to the motor terminal.
Fault1 LED is on when Over-current or Over-temperature conditions occur.
Fault1 LED is flashing when under voltage condition occurs. Check AC voltage is selected correctly
Fault2 LED is on when the motor power is removed.

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Commands
Set RS232 communication protocol correctly and de-select the test mode in the dip switch to enter
command mode.
The following are a list of commands that are accepted over the RS232 input. The small x's after a
command stand for numbers that can be entered. The alpha characters must be capital. The command
is entered by following a Space key. See examples.
MC_A100_V100_G_
The above program will set motor to move in continuous mode, 10 rev/sec² acceleration, 1 rev/sec velocity.
Each command is followed by a space represented by _ (underscore).
Axxxx
Acceleration
This is in rev/sec/sec the least significant digit is in 0.1 rev. The drive does not accept a period to
locate the decimal point. Thus accelerations from 999.9 to 0.1 rev/sec² are represented by the 4 integers.
The least significant bit represents 0.1 multiples of acceleration.
Example A255 sets the acceleration to 25.5 rev/sec²; A3 sets the acceleration to 0.3 rev/sec². The
acceleration should be set after each move is completed. In the distance mode the acceleration should not
be changed while the motor is moving.
CF
COMMAND CURRENT OFF
Removes power from the motor and turns FAULT LED 2 on. This removes motor torque so the load can be
moved by hand.
CN
COMMAND CURRENT ON
Puts power back on the motor. If the CF command is issued this command should be issued prior to doing a
move.
Dxxxxxxxx
Distance
The distance is in motor steps (25600 per revolution. Valid numbers are ±2.000.000.000). The
distance is a 32 bit number internally. Putting in larger numbers will cause incorrect moves. The distance
command is only applicable in the position mode (MI or MA). The distance is in reference to the current
position.
Example
MI A100 V100 D256000 G

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D256000 will set the move to 10 revolution CW,acceleration at 10rev/sec²,incremental move; a D-
256000 is 10 rev CCW. The distance must be entered before each move. There is not a default distance
and it is reset after each move. Do not enter a distance while the motor is moving.
G
GO
This tells the unit to start the move. It calculates the ramp distances at this time for incremental moves and
enables the limit in the direction of travel.
Example see MA, MI and MC commands
GH
GO HOME
Seeks the CW edge of the home limit at the previously specified velocity, acceleration, and direction. Always
specify the CW direction to ensure full travel search. If H- (CCW) direction specified the sequence is
terminated if the CCW limit is found. The motor will continuously move after HOME sensor is reached until
the home sensor is cleared.
Example
H+ A50 V200 GH
The unit uses an acceleration of 5rev/sec² and a velocity of 2rev/sec and moves in the CW direction looking
for the HOME sensor. If the sensor is reached it stops and then continues in the CW direction at 0.1 rev
/sec until the limit sensor is cleared. If the unit senses the limit before the home sensor on the initial move
the drive stops and then drives CCW until the home sensor is reached. It then stops and moves CW at
0.1rev/sec until the home sensor is cleared. If the drive finds the CW limit and then the CCW limit without
finding the home sensor the sequence is terminated.
Hx
Set direction
H is followed by a "+" or "-" to indicated CW and CCW motor rotation respectively. This is used
mainly in the MC mode to set the motor rotation direction. The H must be followed by a + or - to be valid.
MA
MODE ABSOLUTE
This puts the drive in the absolute position mode. The drive performs a trapezoidal move based on the
acceleration, velocity and distance parameters entered. All distances entered are respect to the systems
absolute position counter. Thus if a PZ command is issued, the internal counter is zero. Entering a distance
off D2000 would cause the drive to move CW 2000 counts. Then entering a distance of D4000 would cause
the drive to move 2000 steps again or move from the 2000 to 4000 absolute counter position. A distance of
D-2000 would now cause a move of 6000 counts in the CCW direction. So the absolute counter reads -
2000.
PZ MA A50 V200 D2000 G
D4000 G
D-2000 G
MC
Mode continuous

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This puts the unit in velocity mode. The unit will accelerate to the velocity entered. New velocity values may
be entered while the motor is running. As soon as the new velocity is entered it becomes the target velocity
whether the previous velocity had been reached. The acceleration may also be changed while the motor is
running.
Example
MC A100 V500 G; after the G is entered the motor accelerates to 5 rev/sec at 10 rev/sec/sec. A new
acceleration and velocity or just velocity may now be entered and it will accelerate to the new value.
Entering A20 V100 would cause the motor to decelerate from 5 to 1 rev/sec at 2 rev/sec/sec.
MI
MODE INCREMENTAL
This puts the drive in the incremental distance mode. The drive performs a trapezoidal move based on the
acceleration, velocity and distance parameters entered. If the distance entered is not great enough to allow
the motor to reach velocity with the acceleration given the velocity profile will be triangular and accelerate for
1/2 the distance and decelerate for the other half.
Example
MI A100 V1000 D1000000 G
The motor will accelerate for 128000 steps (5 rev); run at 10 rev/sec until the motor has traveled 872000
steps and then start decelerating. If the distance in the above move is changed to 200000. A100 V1000
D200000 the motor will accelerate until the motor reaches 100000 steps and then decelerate.
PZ
Zero absolute position counter
Set the position counter to 0 (800000 hex). This allows the user to establish the zero position. This should
be done after a home command. On power up this counter is set to zero.
RD
REPORT POSITION
The contents of the 32 bit position counter are sent back in decimal format. A +0 is the power up zero
position, +1 is one step positive and -1 is 1 step negative. This counter will roll over at max count. The
counter can be read while the motor is moving but no guarantees are made on data integrity since the count
could change during the reading and conversion to ASCII.
RD response +25600
RL
Report Limits
The contents of the limit status registers are sent in two hex values. These are located in bits, 0, 1, and 2. If
the bit is 0 then it is active.
bit 0 = limit -
bit 1 = home sensor
bit 2 = limit+
RL response L03.
Limit- and Home sensor are 1

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RS
Report Motor status
Sends out the motor status in hex. It tells whether the last movement was acceleration or
deceleration, whether the motor is running and the mode (velocity or incremental).
b0 motor direction 1 = positive
b1
b2 continuous mode = 1
b3 incremental mode = 1
b4 absolute mode = 1
b5 accelerate = 1
b6 running = 1
b7
RS response S03
S
STOP
This causes the motor to decelerate to a stop in either the velocity or position mode.
Txxx
Use this command followed by a space key to set test speed after power up. T100 sets the test speed to
1rev/sec. T000 will return to default speed. Three digits must be entered otherwise the command will be
ignored. . Remember to always enter commands when test mode is not selected by dip switch.
Vxxxx
Velocity
The velocity is in rev/sec. The acceptable range is from 50 to 0.01 rev/sec. Since decimals are not accepted
this equates to a range of 5000 to 1.
Example V1002 represents a velocity of 10.02 rev/sec. The velocity "must" be set before each move. In the
velocity mode (MC) entering a new velocity while the unit is running will cause the drive to accelerate to that
velocity at the last acceleration rate entered. A velocity of 0 will cause the motor to come to a stop.
MC A50 V500 H+ G
The motor accelerates at 5 rev/sec2 to 5.00 rev/sec in the clockwise direction. Entering V1000 after the
drive has reached speed will cause it to accelerate from the present speed to 10 rev/sec.
DN
Movement Done. This is sent by the drive when the motor stops. This can be used by the host as a notice of
move completed.
XDx
Define stored program x . X can be 1-4. A stored program can be up to 120 characters including the
command and all spaces. The program will be stored and kept in memory after power off. It can be executed

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without re-entering after power up. Error checking is not done at this time. The motor should not be running
when a stored program is created.
Example
XD1 MI A50 V200 D500000 G D-100000 V300 A10 G XE
The program defines stored program #1. This program contains 49 characters including the space at the
end. The XE signifies end of the stored program
XE
End of stored program
XE followed by a space will terminate the program and store it into EEPROM.
XRx
Execution of the stored program x.
RXx
Send out stored program x via RS232

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Electrical
Input Power: 95 to 130 VAC 50/60 Hz, 190 to 270 VAC 50/60, switch selectable.
Fuse: 3.5 Amp (located on PC board by voltage select switch).
Output Power: 0 to 2.5 Amps at 40 VDC through an H bridge liner driver. 0-3.5 amps for 3.5 amp version at
20V DC
Motor Compatibility
Motor inductance - approximately 4 mH for a PMC supplied motor. The drive has a minimum inductance of
1mH. However a motor inductance greater than 20 mH will reduce the top motor speed and may cause
stability problems.
Indexer Inputs/output
All input signal are optically isolated and have a current limiting resistor in series. A driving source of 5 volts
will meet this requirement. If a higher voltage source is used a corresponding external resistor must be
added
Fault (error+, error-) is an npn transistor photo-coupled rated at 50V maximum output. The typical current
when on is 1ma. The transistor is on when an over-current, over-temperature or under-voltage- condition is
detected.
The inputs and fault output can be programmed for a different function for OEM customers. Consult the
factory if you have a need for this option.
PMC drives come pre tested and adjusted for the motor that is supplied with the unit. No further adjustments
are necessary.
"DO Not" connect or disconnect the motor with power applied to the box.
Resonances
All stepper motor drives are subject to two oscillation regions; low speed (approximately 1 rev/sec) and mid-
range (approximately 10 to 15 rev/sec).
Microstepping minimizes low speed oscillation. If your load has a high Q and resonates around 200 Hz,
adding extra inertia to the motor shaft may eliminate the problem. Changing the current wave shape may
help tune the motor driver to your motor load combination.
PMC motors and drives have been matched to eliminate most mid-range instability problems.

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0.50
9999
3.50
9.00
0.25
©
Commands
Vxxxx velocity 0.01 to 50 rev/s
Axxxx acceleration 0.1 to 999 rev/sec²
Dxxxxx distance 0 to ±2000,000,000 steps
G go start motion
GH go home
Hx set direction
MC motion velocity mode
MI motion incremental position
PZ zero position counter
RD report position
RS report status
S Stop
RC report software version
CF turn off motor current
CN turn on motor current
RL report limits, home status
RS report motor status
Txxx store power up test speed
Indexer connector: 25 pin D
1. Limit CW+
2. Limit CCW+
9. Fault+
11 RxD
12 RS232 Ret
14 Limit CW-
15 Limit CCW-
16 Home+
17 Home-
21 Fault-
24 TxD
Motor connector: 5 pin terminal block
1. A+
2. A-
3. Gnd
4. B+
5. B-
2175 De La Cruz Blvd. Ste. #1. Santa Clara, CA 95050 [phone] www.premotn.com
© 2018 Precision Motion Controls. Specifications subject to change without notice.
LN3 dimension: inch
Drive Specification
Precision Motion Controls
Performance (unloaded motor)
Repeatability: ±5 arc-seconds (unidirectional)
Accuracy: ±5 arc-minutes (bidirectional)
Step-to-Step Accuracy: ±20 arc-seconds (unidirectional)
Inputs (optically isolated): 5 VDC, TTL typical
Home: Active low level
Limits: Active low level
Output (optically isolated): 30VDC, 5ma max.
Communication: RS232
Environmental –Operating
Driver: 0 to 60 °C measured at the heatsink
Motor: 80 °C measured at motor case
Ambient: 10 to 40 °C, 0 to 95% humidity, non-conducting
Environmental- Storage
Motor + Driver: 0 to 60 °C, 0 to 95% humidity, non-
conducting
Power: 95-130/190-260 VAC 50/60 Hz, 1.2A
Weight: 15 Lbs.
XDx define program x
XE end program
XRx run program x
RXx report program x