Omega FMA 4000 - Manual (Page 18)

The current Flow Alarm settings and status are available via digital interface (see
paragraph 8.3 ASCII Command Set “FMA 4000 SOFTWARE INTERFACE COM-
MANDS”).
5.3.5 Relay Assignment Settings
Two sets of dry contact relay outputs are provided to actuate user supplied equip-
ment. These are programmable via digital interface such that the relays can be
made to switch when a specified event occurs (e.g. when a low or high flow alarm
limit is exceeded or when the totalizer reaches a specified value).
The user can configure each Relay action from 6 different options:
No Action : (N) No assignment (relay is not assigned to any events and not energized).
Totalizer > Limit : (T) Totalizer reached preset limit volume.
High Flow Alarm : (H) High Flow Alarm condition.
Low Flow Alarm : (L) Low Flow Alarm condition.
Range between H&L : (R) Range between High and Low Flow Alarm condition.
Manual Enabled
: (M) Activated regardless of the Alarm and Totalizer conditions.
5.3.6 K Factors Settings
Conversion factors relative to Nitrogen for up to 36 gases are stored in the FMA
4000 (see APPENDIX II). In addition, provision is made for a user-defined con-
version factor. Conversion factors may be applied to any of the ten gas calibra-
tions via digital interface commands.
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Latch Mode- Controls Latch feature when Relays are assigned to
Alarm event. Following settings are available:
0 - Latch feature is disabled for both relays
1 - Latch feature is enabled for Relay#1 and disabled for Relay#2
2 - Latch feature is enabled for Relay#2 and disabled for Relay#1
3 - Latch feature is enabled for both relays.
Note: If the alarm condition is detected, and the Relay is assigned to
Alarm event, the corresponding Relay will be energized.
Note: By default, flow alarm is non-latching. That means the alarm is
indicated only while the monitored value exceeds the specified
conditions. If Relay is assigned to the Alarm event, in some cases, the
Alarm Latch feature may be desirable.