[Controlling minature servos (Hitec HS485HB) directly from transistor outputs]

Ok, so I managed to get this working with a High Speed Output card using PWM, with a frequency of 50 Hz and pulse widths as quoted above.
This is not exactly high speed, so I wonder is there a PWM function for the Unistream/Unilogic system using a standard transistor output card? If so could someone show me how to access it or an example?

Thanks

Ian

[Controlling minature servos (Hitec HS485HB) directly from transistor outputs]

Hi,
I am trying to hookup some servos for valve control. The servos I have, require three pulse train parameters to output the control action: 600usec, 1500usec and 2400usec to give me -90degree 0 degrees and +90 degrees action respectively.
Looking at the specs for a standard transistor output card (UID-0016T) these seem to able to switch at up to 80us which seems plenty fast enough. I thought I may be able to drive these directly by using a looped timer set at the respective times of 0.6ms, 1.5msec and 2.4ms, but it seems I cant get that resolution(<1ms) out of the timer? Do you know if there is another way to hook these servos up directly to an output card, or obtain timing output of 0.1msec resolution? I don’t think the Unistream system has a pulse train output card, and I am not sure if I could configure a high speed out card either?
My fallback alternative is to use a serial controller for the servos and send out serial commands instead (but I don’t think this solution is as robust). Being new to PLC programming I just wanted to see if anyone had encountered controlling these servos before.
Thanks
Ian