RIO PID Tank Level Control

[nferris]

Hey everyone,

I’m trying to set up a PID to control a tank level. I have the PID set up correctly I think, input is on the correct channel and that info is displaying normally. I have selected my output channel (DO, chan 6) that controls a solenoid valve. When the PID calls for the output, it doesn’t seem to fire the output to start filling the tank. Is there some setting I’m missing that will enable this?

Thanks

[Beno]

Hi there and welcome to the forums.

You are wanting to use a TPO (Time Proportional Output) for your tank level control.
Are you using PAC Control 10.5? It was added in the latest release.
Also are you on EPIC or RIO or something else?
Did you setup the Digital Output channel (Chan 6) to have the TPO function?

[nferris]

It’s a Rio, and I’m using the web interface groov manage to program this. I did not see any TPO settings available in the channel menus. Could I have missed them somewhere? Or is this only available in the PAC control?

[Beno]

Gotcha.
For TPO on a stand alone RIO you will need to use Node-RED.

Setup and run TPO on a RIO

TPO Overview Time Proportional Output (TPO) is a form of pulse-width modulation that allows an analog input signal to control a digital output signal using on/off control to constrain the analog signal. The digital signal is modulated with a time constant from zero to one hundred percent. In the most basic of descriptions, think of it as a temperature probe in an oven and the TPO is switching the heating element on and off to control the oven temperature to a given set point. While you can do…

[nferris]

Ok, thanks, I’ll read up on that solution.

[nferris]

I read the TPO setup with Node-Red, is there any plan in the future to make this functionality available in the groov manage side for PID loops? That would be super useful to not have to go the long way round to accomplish the same thing.

[Beno]

Of course, yes. The Node-RED flow is just a work around until we can get the TPO configuration in the groov Manage interface.

[nferris]

Have the PID loops in groov view had the outputs enabled or do you still have to use NR to do that?

[Beno]

Don’t quite follow your question, so here are some hopefully helpful pointers.
You can enable them in groov Manage. Once you set up the input, output, type, P, I, D and set point, they will start running at the scan rate you set.

To see the input and output values in groov View you can add the RIO as an I/O unit and connect your groov View trends and text etc to that I/O unit.
To see the P,I, D etc in groov View you will need to move them via Node-RED and the groov View data store.

[nferris]

Not sure if you’re referring to my comment but it was in reference to this thread:

RIO PID Tank Level Control

Hey everyone, I’m trying to set up a PID to control a tank level. I have the PID set up correctly I think, input is on the correct channel and that info is displaying normally. I have selected my output channel (DO, chan 6) that controls a solenoid valve. When the PID calls for the output, it doesn’t seem to fire the output to start filling the tank. Is there some setting I’m missing that will enable this? Thanks

[Beno]

Ah, gotcha.
(I moved the thread to make it clear).

The TPO (not PID) is still needing Node-RED for now.
TPO has been added to PAC Control, but if you are using the RIO standalone then you still need to use Node-RED to set it up.