What are the symptoms of a DCS system failure?

Is it the operation station cable or the control station cable? A communication failure between the control station and the card will result in the card performing an action

Does a control station refer to a controller? It refers to the cable between the controller and the operation station.

The control station consists of the controller and the I/O card cabinets; a communication failure between the operation station and the control station does not prevent the cards from functioning. The operation commands simply cannot be sent to the site, nor can the status there be monitored

This post was last edited by elmerscut on 2015-8-3 20:13. I would like to ask: Are the symptoms observed on the DCS operator station the same for both fault conditions – communication failure between the operator station and the control station, and power loss of the control station? As the main operator, how do you distinguish and make judgments?

The last edit to this post was made by Sichuan Instrumentation Beginner on 2015-8-3 at 20:48. When the operation station is disconnected from the control station, it is usually only possible to see no information regarding the status of the instruments and equipment on site; production must then be carried out in a \"blind\" manner. Someone needs to go to the site to read the instrument data, manually start and stop pumps, and operate the control levers. Some system developers write certain logic or calculations in the host computer; if communication with the control station is lost, it will affect the control logic associated with that part. If the control station loses power, it becomes very dangerous; it’s like a commander suddenly suffering from a stroke, causing chaos everywhere. The upper-level system can no longer receive any data either. At such times, it is necessary to activate emergency procedures for production in order to ensure safety and environmental protection. If the control station has a redundant design and only one circuit loses power while the other continues to operate, then it’s fortunate – production will not be disrupted; restore power as soon as possible.

Thank you! I want to know, as a DCS operator, how one can quickly determine whether it is the operation station that has been disconnected from the control station or if the control station has lost power by simply checking the equipment As you mentioned, one is blind operation and the other is cerebral hemorrhage; the approaches to dealing with them are certainly different. But from what the operator sees, it seems like both cases present the same appearance, right? (Since the operation station and the control station are not in the same location and are powered by different substations, it is possible for the operation station to have normal power supply while the control station loses power.) ）

The communication cable is interrupted; command signals from the DCS cannot be sent to the field, and it is also impossible to monitor the status at the field

Do you mean the communication cable between the operation station and the controller? If so, the operator generally uses the stop button on the auxiliary control panel to bring the system to a stop. If it is the cable between the value controller and the IO module, this can be set to output 0 ma in both the normal and fault conditions, that is, in a fail-safe mode.