Hi, all. I've got an issue with setting up a PID on an Omron controller and I was wondering if anyone could give me a hand? Preface: I've been programming with my company for the past five years. We have one system with an Omron controller, the rest are AB PLC5, 500, and ControlLogix, so my Omron understanding is very basic. I've done basic ladder logic changes with the Omron, but this is the first time I've been asked to work on a PID. The problem I have is, this system isn't using any PID right now, so I have nothing to look at as an example, and I've read the applicable manuals, but I'm not getting anything. What I have a system cooking under a vacuum. The Non-Con Blower is creating a vacuum in the cooker. The operator enters the requested pressure (usually -2.5 but the range is -10 to +10), and the Blower should speed up/slow down to maintain that speed. Here are the key components to this system: Pressure Input - Honeywell Pressure Transmitter, -10 to +10psia. This goes back to the PLC on a 4-20mA signal, which goes to a C200H-AD003 (Rack 0, Unit C, Slot 2, point 5). This is assigned to Word/Bit 2126, WR Area D645. The Non-Con Fan is on an Altivar VSD, output 0 - 100% (0-60hz). This is coming from the PLC on a 4-20mA signal, which comes from C200-DA004 (Rack 0, Unit D, Slot 3, point 6). This is assigned to Word/Bit 2137, WR Area D27. Ideally, the system should be set up like so: User enters the requested SP on Wonderware (-10 to +10psia). The PLC compares this number to the number being read from the PV, and outputs the difference to the VSD. How would I go about making this happen? Thanks for anything in advance!
