??? 11/20/06 07:22 Read: times |
#128291 - PCA upsetting Servo Ramp-up Responding to: ???'s previous message |
This is what's being done in my application for a servo system.
1. PCA is configured to HSO mode ( CMOD~02h, CCAPM0~04Dh ). 2. CCAP0h & CCAP0L is loaded with the desired frequency ( example : 3125 produces 1Khz for a 25Mhz crystal ). 2. The PCA needs to produce frequencies from 1Khz to 40 Khz, however 100 pulses per frequency ( 4000 pulses ) in increments of 1Khz. 3. Because its 4000 pulses, its difficult to use a scope. However I'v verified that the values loaded in CCAP0h & CCAP0l do produce the desired frequency in steps of 1Khz. 4. However when we look at the servo encoder feedback signal ( command speed vs actual motion ), it's notice that at certain frequencies the PCA takes time to switch & this causes to motor to loose its momentum. I'm not sure how to get out of this fix now, and any assistance would be much appreciated. Rgds Ranjit |