Set up using AMC AB15A100 drives, brushed DC motor Prototrak Plus with Encoders

new2linux wrote:

Could I start with this diagram and where the tachometers attach, replace with encoder input??

Probably not. 

Old analogue drives with tachometers used a very simple scheme where the control voltage and the tachometer voltage were compared and the motor voltage set accordingly.  Encoders don't output a voltage proportional to speed, so more interfacing is needed. 

Now, if the drives are already conffigured to close an internal velocity loop from the encoder pulses, then what you describe will work. 

But, is it? 
 

andypugh, Many, many thanks!! I have read this response several times,

"are already configured to close an internal velocity loop from the encoder pulses,"

I can/will research this more if necessary, if this will lead to success.

Or if there is a way to use the P1 Connector; location: Pin 8 Current Monitor (Note in AMC AB15A100 Drive manual, says: analogue output signal proportional to actual current output). Is this a potential workaround or part of a successful approach?

Many thanks!! All help is warmly welcomed.

If the drives only mention that current is proportional to input voltage then they are torque-mode drives, and the encoders go straight to LinuxCNC, not to the drives.

This is fairly common, both my servo machines work that way.

Many, many thanks, andypugh, I have read your reply:I have just got off phone with news: I am working with AMC support engineer a question has come up about when booting up LinuxCnc it appears as if I had forgotten to power up the power supply for the AMC drives

Edit: the proper wiring diagram, dated 6/2022 attached.

Many thanks to the forum moderators, members and others that make this forum so informative.
As per suggestion to include pic of the error screenshot attached.

 

Many thanks!!

5i25.0.7i77.0.1.analogoutout0-scalemax not found

This might indicate that the 7i77 field power supply (which runs a small processor on the 7i77 ) might not be connected.

This is (typically) the 24V supply used for limit switches etc, which it is quite reasonable to not expect to need yet. (It doesn't have to be 24V, anywhere from 5 to 30 is OK)