Hello,
(It's long, so bear with me)
First post, by way of introduction I am fairly new to the world of automation but have been reading just about everything I can get my hands on in my free time over the last year. I work in the environmental remediation industry where most of our equipment is still operating in the stone age - place remote machines that have to operate 24/7, then send a tech every two weeks to see if they are still on. If not, no one gets paid and no one is happy. Chances are, you won't have a clue what the problem was, either, and have to send a more highly trained tech or specialist to figure it out. Or it could have just been a momentary power outage that dropped the seal-in circuit out...
So - I had the "brilliant" idea of designing a system that is better than the status quo in this industry, which my boss suprisingly gave me a budget for. VFD to vary process flow instead of a physical recirculation valve, an HMI and datalogger, PLC control of very simple logic, and several discrete temp controllers.
Now to my question - which I've had a hard time finding anything out about - I have a Click analog PLC, 2 SOLO temperature controllers, and a GS3 (Automation Direct brand) VFD. The PLC can communicate via MODBUS RTU protocol over RS-485. I have a test station set up where this is suppose to happen before it goes into the prototype machine.
Goal: Read operating parameters from VFD, Send Frequency to VFD (RS-485) - Start/Stop will be achieved through digital inputs.
Read temperature and duty cycle from each temp controller. Would be nice to be able to change set point, but not necessary (RS-485)
1 device (VFD) worked perfectly. Added the first temp controller, worked sometimes. Added 3rd device (temp controller 2) and the RS-485 couldn't send or receive anything.
I know this has to do with correct interlock but I haven't found any good information on how to do this with send and receive from more than 2 devices, and have only been marginally successful trying to imitate that logic.
Any suggestions? What can I provide that would make answering this question easier? The cable connection is very short and noise/connection/port setup are all fine. I'm almost 100% this is just an interlock problem. Thanks in advance!
(It's long, so bear with me)
First post, by way of introduction I am fairly new to the world of automation but have been reading just about everything I can get my hands on in my free time over the last year. I work in the environmental remediation industry where most of our equipment is still operating in the stone age - place remote machines that have to operate 24/7, then send a tech every two weeks to see if they are still on. If not, no one gets paid and no one is happy. Chances are, you won't have a clue what the problem was, either, and have to send a more highly trained tech or specialist to figure it out. Or it could have just been a momentary power outage that dropped the seal-in circuit out...
So - I had the "brilliant" idea of designing a system that is better than the status quo in this industry, which my boss suprisingly gave me a budget for. VFD to vary process flow instead of a physical recirculation valve, an HMI and datalogger, PLC control of very simple logic, and several discrete temp controllers.
Now to my question - which I've had a hard time finding anything out about - I have a Click analog PLC, 2 SOLO temperature controllers, and a GS3 (Automation Direct brand) VFD. The PLC can communicate via MODBUS RTU protocol over RS-485. I have a test station set up where this is suppose to happen before it goes into the prototype machine.
Goal: Read operating parameters from VFD, Send Frequency to VFD (RS-485) - Start/Stop will be achieved through digital inputs.
Read temperature and duty cycle from each temp controller. Would be nice to be able to change set point, but not necessary (RS-485)
1 device (VFD) worked perfectly. Added the first temp controller, worked sometimes. Added 3rd device (temp controller 2) and the RS-485 couldn't send or receive anything.
I know this has to do with correct interlock but I haven't found any good information on how to do this with send and receive from more than 2 devices, and have only been marginally successful trying to imitate that logic.
Any suggestions? What can I provide that would make answering this question easier? The cable connection is very short and noise/connection/port setup are all fine. I'm almost 100% this is just an interlock problem. Thanks in advance!