I am using the PXI-7344 Motion Controller to drive three stepper motors and 5 servos. I am running into unexpected problems with PXI-7344 Motion Controllers to drive stepper motors.
Steppers are configured as CW & CCW and open loop.
At first,I started with two PXI-7344 Motion Controller for 8 axes control.
But two axes stepper control with two axes servo on a one PXI-7344 gave a problem that one of stepper axis speed was faster than a given command speed on a certain moment during all four axes were running simultaneously. In spite of new firmware upgrade, that problem could not be fixed.
So now I am using three PXI-7344 Motion Controllers for 8 axes.
The second problem is the output voltage level of stepper pulse.
PXI
-7344 Motion Controllers and stepper amplifiers are interfaced with "open collector".
Stepper amplifiers are driven with +24Volts and +24Volts is supplied from stepper amplifiers.
As hooked up to a scope to monitor,stepper amplifiers are working correctly as the output voltage level of stepper pulse over +15V for a rise but incorrect as below +15V causing fast speed and more pule move than the given command.
The problem is that the pulse voltage level is not uniform for axes on PXI-7344 Motion Controllers. For an instance,Axis one always gives +15V pulses but other axes are not. And other PXI-7344 Motion Controller's axes always gives only around +13V level pulses even if it is new one.
So it could not be replaced with other one except that gives +15V level pulses.
Why does such strange thing happen?
And how could that problem be fixed?
Any help would be greatly appreciated!
Thanks in advance.
Choe