Issue
A sensor connected to a DMS system displays the letters INH to the right of the real-time display. What does this mean and how can it be removed?
Environment
DMS
Cause
It is unknown how the INH appeared on the point. There are at least three ways to do it with programming but none were found in the database.
The INH is short for 'inhibit'. It prevents a point from generating alarms or changing conditions even though an alarm or change of condition exists. It is useful during times when maintenance is being done on the associated HVAC system or if the HVAC system is scheduled off. It prevents nuisance alarms.
Sometimes it gets applied after a database glitch during a loss of power or communications. This situation is rare but it can occur.
Resolution
To remove the INH and allow the sensor to alarm and change condition, it must receive the ENINH command. There are several ways to apply the ENINH command. The quickest way is to use command mode.
In OPRIF,
- use the up and down arrow keys to highlight the sensor with the INH applied to it.
- press F8 to enter command mode
- type ENINH then enter
- press F8 to exit command mode
- allow OPRIF a few seconds to update and refresh the sensor on the screen
