Richard Everett wrote:
Thanks Tim. Two things bother me about the G901 boards (or the G340 drive which includes that board). It is a PLL (phase locked loop), which means it needs several pulses before it "locks on" to that frequency. I am not sure, but this might be a problem on really slow moves.Mariss has confirmed that at low rates, like 10 steps/sec at the input, it outputs the required number of pulses in a busrt, then stops until the next pulse comes in. The second thing is, by using this pulse multiplier board, I am sorta losing the fine resolution that these encoders provide. Are my interpolated circles going to be somewhat more stepped?Yes, I think so. At $39 per axis for the upgrade, I am looking at about $150 per axis for drives (ignoring the fact that I have two G320 drives for the moment). Is there a true +/-10V input digital servo drive that takes quadrature feedback in the $150 to $300 per axis price range? I looked around on the copley website, but all I saw that seemed to fit this was the model 405, which is only 5 amps continuous, 10 amps peak. I would not mind getting the servo to go board (to have a closed loop system) if I could find amps to fit my motors.What about the JSP-090-20 (for up to 90 V) or the JSP-180-20 (up to 180 V). I have no idea what they cost. They don't take a tach, but with your encoder resolution, that may not be needed. There's also the 413, 422, and 423 where a tach could be easily added to the motor with a miniature belt, like I did. Jon |