Is there an example out there of driving a bi-filar stepper motor from a NI PCI-6601?

[mmv]

Is there an example out there of directly driving the coils of a bi-filar stepper motor from a NI PCI-6601? I will connect logic that converts the 4 bit output patterns into two coil enables and two coil direction signals for the coil driver FETs. I would like to output the sequence of 8 4-bit (half step) patterens stored in an array at a step rate of up to 1100hz or (full steps) at up to 550hz. Can I do this with a PC and a PCI-6601? I've done this type of motor control with an 8 bit MC68HC05 in the past and I'm trying to do the same thing with LabVIEW without using a motion controller board. I understand that this may not be the perfect way to do this and it would be non-deterministic but the motion should be slow enough to prevent trouble and I will use a sequence of limit switchs and a wheel driven encoder to give absolute position references.

What I envision is a VI to select the next 4 bit pattern from the stored last step position and a direction signal. Previously I've used an interrupt service routine to select and load the next 4 bit pattern and reload a countdown timer for the next pattern update. That worked using assembly language and a countdown timer triggered interrupt service routine. I expect others have tried to do this before. is there a straight forward way to do this?

Thanks in advance for your help.

[David L.]

Hi mmv,

If you would like to do a series of outputs representing steps for your motor, we have a shipping example which does what you are looking for and takes minimal alteration. After opening LabVIEW, go to Help » Find Examples... » Hardware Input and Output » DAQmx » Digital Generation » Cont Write Dig Port-Ext Clk.vi. I have attached a slightly altered version which shows the values in decimal, along with binary, and only outputs a U8 instead of a U32. This example uses an external clock, so you will be able to control the rate of output.