The alarm signal for levels below 4MA at the site is cleared
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Some of the instrument signals at the site are below the 4MA alarm level; how can these alarms be eliminated?
It is an alarm from the control room DCS due to the field instrument signal being below 4 mA； Is it still the case that the field instrument reads below 4mA, triggering an alarm on the instrument’s display?
When the field instrument signal is below 4 MA, it is a DCS alarm.
Values below 4 mA can be displayed as 0, which helps to prevent unnecessary alarms in the DCS
The alarm at levels below 4 mA occurs because the default configuration for the bottom section is usually between -5% and 105%. It is possible to set the minimum value in the DCS configuration to 0%, rather than -5%, so as to prevent low values from appearing during DCS signal conversion. It is also possible to change the value in the HART communication settings field at the table header to 0%, or to a slightly higher value of 1%–2%; in that case, the output from the circuit board will not be low
This post was last edited by jlshnlhj on 2021-9-13 at 11:57. Correction: The alarm for values below 4mA is an IOP alarm; when the setting is 0%, it indicates an alarm for values below 4mA. -5% corresponds to values below 3.2mA, -10% corresponds to values below 2.4mA, and the lowest value is -25%. If alarms are triggered frequently, the 0th bit should be low; if it is within the error range, the lower limit can be set to -10% or -15%.