Process Alarm And Latching - Spectrum Controls Micro800 2085-IR8-SC User Manual

3-26 Chapter 3: Configuring the Micro800 Expansion I/O 2085-IR8-SC Using CCW
User's Manual Pub. 0300321-01 Rev. A
•
For the Disable option, an open circuit condition is not reported. Also,
the periodic open circuit detection does not take place.
•
The Channel Fault bit and the OC bit are cleared once the open circuit
condition on the channel has been resolved. The time to update the bit
status is controlled by the 3-second or the module scan rate, whichever
takes longer.
•
An open circuit condition may also be triggered by feeding channel input
resistance or temperatures well beyond the defined limit values indicated
in the Points and Limits for Input Type.

3.6.9 Process Alarm and Latching

The Process Alarm feature allows you to enter a pair of user-defined high and
low values for the module to monitor between the channel input reading. The
maximum range you may enter is based on the limits of the selected Input Type
and the Data Format. This alarm feature can also be used as an Over or Under
Input Type Limit alarm. Once the channel input reading is equal to, or
greater/less than, the user-defined value, the corresponding channel Process
Alarm status bit is set in the input table.
The lowest value for the Process Alarm Low Value you can set is the low limit of
the selected Input Type. The same requirement applies to the highest value for
the Process Alarm High Value. It can be set only to the high limit of the selected
Input Type.
The Process Alarm Latching decides whether the status bit is to be cleared
automatically or kept latched until manual cleanup is triggered by a user or the
ladder software. The latching feature is useful for capturing whenever the
channel input reading has reached, or exceeded, the user-defined value.
The latch can be cleared by making a bit value transition on the control bit in the
output table.
Index Process Alarm &
Latching
0 Disable Both
1 Enable Alarm Only
2 Enable Both
3 Invalid
The firmware reports a configuration error if an invalid Process Alarm option is
entered in the configuration table:
•
If Option 0 is selected, both the Process Alarm and Latching
functionality are disabled, and the validation on the channel Low and
High Process Alarm Values is ignored.
•
If Option 1 or 2 is selected, the firmware reports a configuration error if
any Process Alarm value set in the configuration table is invalid as
follows:
-
The Process Alarm Low Value is equal to, or greater than, the
Process Alarm High Value.
-
The Process Alarm Low Value is less than the low limit of the
selected Input Type.
Note
Default