Killer (Customer) asked a question.
Hi,
I have an existing system with a third party, proprietary, motor controller being controlled by a Linux microcontroller. I am using a encoder as input into the motor controller and I issue API commands via a serial interface to the motor controller to make moves, stop etc.
I would like to replace the Linux microcontroller with a PLC / Motor Controller combo, and take modbus commands from an external source to initiate motion.
Can I just hook the encoder up to a quadrature channel on the PLC and use a PID loop to control a DC motor controller with a voltage output? Basically I want a user to be able to set a modbus register to a desired position and have the PLC make it so.
The motor is a 12vdc motor, average current consumption, during a move is 9A, peaking around 15A. Does anyone have a motor / controller suggestion?
Some VFDs have a PID input as well as a PLC inside them and encoder inputs. While you are using a 12v DC motor, there may be a more advanced DC motor controller available that has all these things. If you can find something like that, you would be able to do everything within 1 unit.
Briefly looking at some of the DC drive accessories on the Automation Direct website it looks like some have analog input modules that could take an analog signal controlled by PID from a PLC. Some others have encoder input on them, but are for higher voltage motors. So I am sure a drive like you need is available somewhere.