G320 Setup Electrocraft 60V Servos

[Noah]

Hi, I am setting up my G320 Drive for an Electrocraft 60v Servo. I have been going through the testing procedure in the installation notes with no problems until I came to the point where you connect power to the servo. As soon as power is connected the servo will jump then wait about 3 seconds and then take off at I think its max speed. When any command is given the motor starts oscillating randomly and the drive faults. I am quite sure the encoder is good because when the motor is not connected, the drives faults every three seconds when a pulse source is given as stated. The gain and damping trimpots do seem to have random effects on this but I can't seem to find any position where the motor actually stays still. Anyone know what is wrong?

[Al_The_Man]

I am not familiar with the G320 drives, but usually run away is caused by either a tach reversal, if no tach is fitted and the loop is closed by encoder alone, then the encoder is not phased right.
Firstly, if you have a tach fitted you should power the system up with ensuring no (or zero) signal command is issued.disconnect the command input if neccesary and connect to ground or common. Power up and if the motor runs away change the tach lead polarity and retry, when you power up, try turning the shaft you should meet some resistance. Once the tach is correctly phased (if you have one) then connect the system and if a command is given and the motor oscillates jumps or takes off, it is most probabally encoder phasing, this can be corrected by changing the A & /A leads if you have a differential encoder, or A & B if non differential.
Al

[kong]

If Als solution does not fix it, then exucse the stupid question, but is the encoder firmly attatched to the motor? I had this problem once when the encoder coupling became loose, therefore the gecko was turning the motor in an attempt to get feedback from the encoder, which wasn't turning.

[Noah]

Thanks guys, I got that fixed.

[svenakela]

And the problem was?

--Sven

[ESjaavik]

I agree with you Sven. Some people don't bother telling what the solution was. That could help others with a similar problem. There's another thread regarding a power supply blowing fuses. I guess it's solved also, because the silence suddenly hit that thread too. But only one person learned from it.

[Noah]

Sorry guys. I did not consider that. My servos are using 9-pin serial port connectors for the encoders. I assumed that the pin numbers for these connectors were standard, but it seems not. After checking the spec sheet on my servos pin 1 for the encoder was actually pin 5 for my cable (the gender changer switched it around). Once I wired the four encoder leads in reverse, everything worked fine.