Thanks for your tip djs,
The system is expected to be in auto during normal operation. Operation in manual mode will initiate an indication in the control room. We do not want to distract the operator too much.
I get your point though and that sounds like a robust design.
Thanks IRstuff. Actually, loss of the remote set point signal is going to be a rare occurrence but I am considering it in my design so I can improve the reliability and availability of my system.
I think I have come up with a modified program and I hope to test this tomorrow and feed you guys...
Hello rmore. You might need to check earthing. So each manufacturer will have its earthing requirements which might be different from the ones you use. For instance, not doing your earth at both ends and doing it at only one point could case earth loops and all.
So you have to check your...
Thanks for the reply DonUK. I do not have data logging facility as part of this simple control system but what I will try is to use the Sensor Break Mode facility.
If configured as ‘Hold’ the output of the loop will stay at its last good value.
On exit from sensor break the transfer is...
Is your system performing a safety critical function?
Try and look at reliability figures of the HMI you are using. Some HMI design ensure that no more than 1 in 10 failures of its server than can jeopardize the integrity of information being acquired, logged and displayed
Thanks for your reply.
What I am aiming to achieve is to prevent the valves from closing (being driven fully shut) when there is a sensor break. It is an undesirable state for the process and so I need to program this anomaly out, if you see what I mean.
I have an alarm that will warn me that...
Hello All,
I have this challenge with a controller I am trying to program. I need to understand what is actually happening and that is the reason why I have created this forum. I plan to contact the manhufacturers of the controller for help in addition but I do not want to be lazy. I want to do...
Hello,
I have been able to get the valves to move, thanks to the explanation below
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Proportional Band: The amount of change in the controlled variable, expressed in engineering units...
I am using a Eurotherm 3504 controller to controll a valve based on input pressure.
See details:
PV – Pressure transmitter input (0-5 bar), 4-20mA (i/p to controller)
Module 1 – Remote setpoint (0-5 bar), 4-20mA (i/p to controller)
Module 2 – Analogue output of valve actuators position to...