7.1.2 Description of operation
As programmed like independent setpoints, the alarm outputs activate when the display value reaches the user-programmed
value. The independent alarms programming requires definition of the following basic parameters:
a. HI/ LO ACTING MODE.
In HI mode, the output activates when the display value exceeds the setpoint level and in LO mode, the output activates when the
display value falls below the setpoint
b. PROGRAMMABLE TIME DELAY or HYSTERESIS.
Each output action can be deferred by a programmable time delay or hysteresis level.
The time delay is the time that takes the output to activate after passing through the setpoint in the up or down direction, while
the hysteresis band will be selected asymmetrical i.e. only acts on the output deactivation edge.
The delay is programmable in seconds, from 0 to 99.
The hysteresis can be programmed, in counts, within the full display range. The decimal point appears in the same position as
programmed in the display configuration module.
The figures 1 and 2 show the time delay action (dly) and the asymmetrical hysteresis action (hys-1) of two alarms (SET1 and
SET2) programmed to activate in HI mode (OUT1) and LO mode (OUT2)
To Next Page
Loading...