How to set the AI alarm dead zone for Zhejiang University Zhongkong 300 system
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For example, the current liquid level is reported as 1700 mm when it’s high and 1000 mm when it’s low. What should the deadband value be? Sometimes the liquid level fluctuates around 1700 mm, resulting in many alarm notifications. How can this setting be adjusted to reduce the number of alarms and alarm records? I still don’t understand how to set the deadband and deviation alarms in a reasonable manner
Actually check the liquid level curve to see what the range of fluctuations is. If it does not affect the operation of the process and frequent alarms are not desired, then set that range as a dead zone. Of course, essentially this is a range determined by the manufacturing process, not something that should be decided by the instrumentation team.
I don’t understand what a dead zone means right now. If the process gives me a fluctuation value of 50 mm, how should I set the dead zone value? Will the number of alarm records decrease after setting it?
This post was last edited by jlshnlhj on 2022-4-29 at 15:53. The dead zone is generally 2%-5% of the range. It means that the PV must exceed this range for the alarm to be cleared. For example, if the lower limit is 1000 and the dead zone is 50, then a value of 1050 or higher is required to trigger the removal of the lower limit alarm; this helps to avoid frequent alarms as PV fluctuates around the alarm threshold. The deviation in a deviation alarm refers to the difference between PV and SV (or SV and PV). An alarm is triggered when PV deviates from SV by a certain amount. The specific values are generally determined by the process. Those with strict management cannot be changed arbitrarily, while those with general management can be adjusted according to actual needs (such as an increase or decrease in production volume)
This post was last edited by feng*aosa on 2022-4-29 at 18:02. The liquid level dead zone refers to low or high liquid levels that cannot occur. For example: level measurement from 0 to 2000 mm, with the outlet of the tank at a height of 200 mm. In actual operation, it is impossible for the liquid level to drop below 200 mm; in such cases, a dead zone of 200 can be set ； If it is necessary to prevent air from entering the outlet of the storage tank, the dead zone can be positioned a bit higher. Similarly, if there is an overflow port at 1800 mm, a liquid level above 1800 will not occur. A dead zone is set to alert the operator that the liquid level has actually reached the bottom. If the zero point of the level gauge is already above the dead zone, the dead zone can be set to 0. .