
© 2022 All rights reserved. Data subject to change without notice.
43
Rev. C | 2022.02
FCS - Operation Manual
Set:
Select to force the relay into its active state immediately upon pressing Save. The
override will continue for the duration of the time specified.
Clear:
Select to force the relay into normal mode, to not activate even if it is configured
to do so. For example, the relay will NOT activate if the gas readings reach or surpass the
alarm set point. The override will start immediately upon pressing Save and will continue
for the duration of the time specified.
The Save button will turn green after a change has been made. If you are going through more
relays on the same screen, the system will auto save when you press the + or - to proceed or
return to the next relay number. If you press Home or Back, the change will not be saved. You
can choose to press Save if in doubt.
To continue changing or reviewing the settings for each relay press use the + to proceed to
the next relay number.
NOTE:
A latched relay cannot be overridden.
The override status along with the amount of time left for it to be in that state can be viewed
by pressing on the Relay Status Bar and using the + or - buttons to scroll to the relay that has
been overridden.
8.4 How to Clear a Latched Relay
A latched relay is a relay that has triggered an event and will remain active until it is manually
cleared/turned off. This functionality is commonly used in situations where the desire is for
the alarm to remain on until it is properly dealt with by someone who knows what they are
doing. It prevents someone turning off the alarm, ignoring the reason for it and continuing
to work in a potentially dangerous area. This feature could be used for safety interlocks
where the shutoff of equipment is triggered and latched such as shutting of the ammonia
compressor if there is an ammonia leak.
For more information about enabling or disabling relay latching, refer to Section 8.1 Enable /
Disable Relays, Assign Modbus ID & Change Mode of Operation.
To clear a latched relay, press on the Relay Status Bar. Use the + or - buttons to scroll to the
relay that is latched. Press on the Clear Latched button.