Stepper motor translator and drive circuits typically require STEP
and DIRECTION input signals to operate. These signal can be provided by PLC's, stepper
indexers or stand-alone digital circuitry. The ADR products can be used to provide these
signals using digital I/O and commands to SET and RESET the I/O lines. The host can
then control and keep track of stepper position.
Figure 1. Basic Stepper Motor Application
The demand on the bandwidth of the communication link between
the host and standard ADR products limits step speeds to about 150 steps/second at 9600
baud. To overcome this limitation the ADR2100 has a complete dual stepper motor
indexer built in to provide precise step and direction signals to stepper drive circuits
with minimal use of the communication link between the host and ADR products. the indexer
has the following features;
- Simultaneous control of two stepper motors
- Programmable speed setting ( 0 -1000 steps/second in 10 step/second
- Indexed moves of up to 50,000 steps
- Monitoring of limit switches ( two per axis )
- Interrupt generation ( programmable )
- Emergency Stop function
- Easy to use command set
- Position registers readable on-the-fly
- Speed change on-the-fly
The stepper motor indexer uses port A of the ADR2100 when configured
for STEPPER MODE. A Typical connection of a stepper motor linear slide application is
shown in figure 2.
Figure 2 Typical Stepper Motor Application with ADR2100 as
The limit switch inputs have built in pull-ups allowing use of
mechanical or inductive proximity switches. ( NPN) When limit switches are activated,
movement in corresponding direction is disabled and an interrupt is generated ( if enabled
) The commands ( preliminary list ) to use the indexer are;
Configures PORT A as stepper indexer.
MSddd <cr> ( ddd = 000 to 100 )( ddd*10 =
actual speed setting)
Sets speed of move from 0 to 1000 steps/sec in 10 step/sec
increments. Speed is changable on the fly and has a worst case accuracy of 1%
LAFddddd<cr> ( ddddd= 00000 to 50000 )
Loads stepper motor A move register with steps to move Forward ( CW
LARddddd<cr> ( ddddd= 00000 to 50000 )
Loads stepper motor A move register with steps to move Reverse ( CCW
LBFddddd<cr> ( ddddd= 00000 to 50000 )
Loads stepper motor B move register with steps to move Forward ( CW
LBRddddd<cr> ( ddddd= 00000 to 50000 )
Loads stepper motor B move register with steps to move Reverse ( CCW
Returns present number of steps to finish move of stepper motor A
Returns present number of steps to finish move of stepper motor B
Begins move of both stepper motors.
Emergency Stop, stops all motor movement.
Enables interrupt generation.
Additional features of the ADR2100 may enhance the application such
as using the PWM outputs for motor torque control.
For additional Information please contact Tom Fortin at our Sudbury
office. (705) 671-2652
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