ALARMS (Optional)
The alarm option consists of an additional printed circuit board with nine
terminals. Six of these terminals are the two Form-C relays and the other three
are the two open collector transistors, which act in parallel with the relays. The
two alarms are completely independent with programmable values, hysteresis
(deadband), high or low acting, auto or manual reset, triggering from input or
total, and tracking one another, if desired. If the alarms are programmed to latch
(manual reset), then they will have to be reset either by the front panel or remote
input. The alarms can be made to trigger from the totalizer instead of the input,
to activate external alarms, control valves, etc. Additionally, the alarms may be
programmed to activate an alarm display to alert operators of the condition.
Alarm #1 can be made to track Alarm #2 by enabling alarm tracking. This is
useful in alarm set-ups where a pre-warning control activates before a second
alarm shuts off the process when tracking is programmed. Changing the
shut-off trip value (Alarm #2) automatically changes Alarm #1 so that the
offset between Alarm #2 and Alarm #1 remains the same. Alarm and
hysteresis values can be modified through the optional serial communications
to provide automatic control. The following diagrams depict how the alarms
work with both “HI” and “LO” acting set-ups.
Programming of the alarms can be done in the normal programming mode
“Pro 6” or the unit can be programmed so that the values can only be changed
in the “quick programming” mode.
If the display should indicate an “OLOLOL” or “ULULUL” the alarms will
de-energize, whether they are latched or unlatched.
Note: Alarm Comm. (TBB #8) must be kept isolated from Analog “-”.
-29-
ALARM TIMING DIAGRAMS
To Next Page
Loading...
Need help?
General
