I am working with a click plc (C0-01DR-D) from automation direct. I need to interface with an internal timer but my model does not have any analog inputs. To get an analog input and keep the number of relay outputs I need is going to cost me another $90, so I am looking for a way to use a knob control without one. The tech from automation direct tells me the only way is to find a potentiometer (knob) that does Modbus RTU via RS232 or RS485. So far I have been unsuccessful in my search. if anyone knows of one I can buy, or a way to use a normal potentiometer with the tx/rx port, it would be greatly appreciated.
Hello Newbie in need,
Quick idea from me, you can use Arduino connected to AD5171 Digital potentiometer and also embed Modbus code into the Arduino
so you will have your click PLC talking to electronic potentiometer :
hope this help
Thought about using two discrete inputs? Raise/lower a counter that is the timer set-point.
Set a limit to the ramp equivalent to the longest/shortest time you require.
I assume you can display a number
Start the count up/down by 1 then accelerate with time like a typical digital device set-point.
I'm pretty sure that if a pot with Modbus interface exists, it costs at least $90. I've actually never heard of such a thing. Though you could certainly make one out of Modbus remote I/O and a pot, but that doesn't gain you anything over replacing the Click. I thought they had analog expansion modules anyway?