Under/Over Range Alarms; Open Circuit Detection - Spectrum Controls Micro800 2085sc-IF16C User Manual

3-24 Chapter 3: Configuring the 2085sc-IF16 Using CCW
NOTE
User's Manual Pub. 0300306-02 Rev. B
configuration table.
Set the Process Alarm Low status bit in the channel status struct when the
channel input value is less than the Process Alarm Low Value in the
configuration table.
• If the Process Alarm Latch bit is disabled, then clear the appropriate
alarm status bit when the channel input value is no longer within the
alarm value range.
If the Process Alarm Latch bit is enabled, then clear the appropriate
•
alarm status bit when both of the following conditions are satisfied:
-
The channel input value is no longer within the alarm value
range, and
-
The Set Latch Clear bit in the output table is set.
This bit must remain set until the appropriate Alarm Status bit is cleared.
This bit can then be cleared again. The module does not latch an alarm
condition if a transition from no alarm to alarm occurs while a channel's
Set Latch Clear bit is set.

3.6.4 Under/Over Range Alarms

The alarm is not latched; if the input signal goes back into normal operating
range, the alarm is automatically cleared. This feature applies to all input types.
The under-range and over-range status bits are defined in section the Channel
Status Struct table.
Set the Under-range status bit when a channel input is lower than the
•
Low Range value indicated in the input ranges table.
• Set the Over-range status bit when a channel input is higher than the
High Range value indicated in the input ranges table.
• Clear the Under-range and Over-range status bits when the channel input
is within the Low/High range values indicated in the input ranges table.

3.6.5 Open Circuit Detection

The open circuit detection feature alerts you to an open circuit condition by
setting the open circuit status bit and displaying a high limit, low limit, or zero
data value for the appropriate channel(s) in the input table.
Open circuit detection may also be disabled for any or all channels:
Open Circuit
Index
Detection
0 Upscale
1 Downscale
2 Zero
3 Disable
The open circuit detection behavior depends on the channel input range selection
and the open circuit detection selection bits for each channel:
Note
Default