DO output fault in Yokogawa PROSAFE-RS system
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The ESD used in our factory is Yokogawa’s PROSAFE-RS system. During operation, the DO outputs (used to control solenoid valves) occasionally trigger OOP alarms (with the circuit monitoring function enabled). After checking and confirming that the wiring was correct, turning off the circuit monitoring function resolved this issue. Additionally, when the faulty solenoid valve was used in a DCS circuit, no problems occurred at all. At present, we suspect that the circuit detection function of the DO output from Yokogawa’s ESD system is not well matched with the solenoid valves. We are using FESTO solenoid valves, model: VACC-S18-K4-1U-EX4 ME, order number: 562897. I wonder if any members of this forum have encountered a similar situation? Or are there any ESD systems that also use Yokogawa PROSAFE-RS?
In projects, it is rare to have a direct DO output driving the field solenoid valve; usually, a relay is used in between. Since it has been confirmed to be a false alarm, it can be simply turned off.
Since ESD is involved, this circuit detection function cannot be turned off; it is used to inform the control center whether the valve is in normal condition at the moment
Additionally, it does not drive the load directly via DO; there is a board in between, but it is not a relay in the traditional sense
You selected YES for Detect Disconnection on-site. In fact, if OOP really occurs, the solenoid valve on site will lose power and the device will stop operating.
I certainly know it’s not a relay in the traditional sense; projects usually come equipped with an SRM54D safety relay board. Since there is a relay in between, diagnosing OOP has nothing to do with the solenoid valves on site at all. It is recommended to first understand the principle of the circuit, so that the root cause of the problem can be identified.
Indeed, YES was selected, which activates this circuit detection function. The problem now is that OOP is detected suddenly during normal operation, which causes the entire plant to stop working. However, in reality there is no issue with the wiring; the solenoid valve functions properly even when powered by 24V separately. In fact, even when I set \"Detect Disconnection\" to NO to disable the circuit detection function, the solenoid valve still works normally. So now it is suspected that this solenoid valve and the circuit detection function may not be compatible or may conflict with each other, resulting in occasional false alarms.