Galil DMC-3425 user manual Connect Step Motors, Bga Cr, Amacr, Bc Cr

PRA=-1*(_BZA) <CR>	Move A motor close to zero commutation phase
BGA <CR>	Begin motion on A axis
AMA<CR>	Wait for motion to complete on A axis
BZA=-1 <CR>	Drive motor to commutation phase zero and leave motor
	on

Method 3. Use the command, BC. This command uses the hall transitions to determine the commutation phase. Ideally, the hall sensor transitions will be separated by exactly 60° and any deviation from 60° will affect the accuracy of this method. If the hall sensors are accurate, this method is recommended. The BC command monitors the hall sensors during a move and monitors the Hall sensors for a transition point. When that occurs, the controller computes the commutation phase and sets it. For example, to initialize the motor upon power or reset, the following commands may be given:

SH <CR>	Enable motor
BC <CR>	Enable the brushless calibration command
PR 50000 <CR>	Command a relative position movement
BG <CR>	Begin motion. When the hall sensors detect a phase
	transition, the commutation phase is re-set.

Step 8c. Connect Step Motors

In Stepper Motor operation, the pulse output signal has a 50% duty cycle. Step motors operate open loop and do not require encoder feedback. When a stepper is used, the auxiliary encoder for the corresponding axis is unavailable for an external connection. If an encoder is used for position feedback, connect the encoder to the main encoder input corresponding to that axis. The commanded position of the stepper can be interrogated with RP or DE. The encoder position can be interrogated with TP. Only the DMC-3415 allows the use of the main encoder input with a stepper motor. The DMC-3425 does not have this option.

The frequency of the step motor pulses can be smoothed with the filter parameter, KS. The KS parameter has a range between 0.5 and 8, where 8 implies the largest amount of smoothing. See Command Reference regarding KS.

The DMC-3425 profiler commands the step motor amplifier. All DMC-3425 motion commands apply such as PR, PA, VP, CR and JG. The acceleration, deceleration, slew speed and smoothing are also used. Since step motors run open-loop, the PID filter does not function and the position error is not generated.

To connect step motors with the DMC-3425 you must follow this procedure: Step A. Install SM jumper

Install the jumper SMX at location JP2 to enable stepper motor operation on the DMC-3415. For the DMC-3425-Stepper, the jumpers should be loaded on SMX and SMY. For a discussion of SM jumpers, see section “Step 2. Configuring Jumpers on the DMC-3425”.

Step B. Connect step and direction signals from the controller to respective signals on your step motor amplifier.

The DMC-3415 outputs STEPX (step) signals on the ICM-1460 terminal labeled ACMD, and outputs DIRX (direction) signals on the ICM-1460 terminal labeled ACMD2.

26 • Chapter 2 Getting Started DMC-3425