Example Alarm Settings - Omron CJ Series Operation Manual

Using the Alarm Output Function

3-10-4 Example Alarm Settings

Alarm Mode and
Alarm Hysteresis
1,2,3...
Loop 2, Alarm 1 SV
62
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Restarting the Standby Sequence
The standby sequence will be cleared once the PV leaves the alarm range,
but the standby sequence will restart (reset) in the following situations:
• At the start of operation (when power is turned ON or the Unit is restarted)
• When the alarm SV, input calculated values, or set point is changed
• When the Output OFF Bit turns OFF
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Summary of Alarm Operation
The following timing chart shows the operation of alarms with a standby
sequence. In this example, the alarm mode is Upper and Lower-limit Alarm
with Standby Sequence.
Alarm mode: Upper and Lower-limit Alarm with Standby Sequence
Alarm SV
(upper)
Alarm goes OFF
by hysteresis
Standby
sequence
cleared
Alarm goes OFF
by hysteresis
Alarm SV
(lower)
Alarm output
The alarm mode and alarm hysteresis for loops 1 and 2 are set as shown in
the following table.
Loop Alarm
Loop 1 Alarm 1
Alarm 2
Loop 2 Alarm 1
Alarm 2
1. DM Area word m contains the loop 1 alarm mode and loop 2 alarm mode.
Set D (m) to 3218.
2. DM Area words m+2 through m+5 contain the alarm hysteresis settings for
loop 1 and loop 2. Set the appropriate values for the hysteresis based on
the data format (BCD or binary) set for the Unit.
3. To enable the new settings, restart the Unit or turn the power OFF and then
ON again.
DM Area word m+20 contains the loop 2 alarm 1 SV. To set this alarm SV to
20 ° C, set this word to 0020 if the data format is BCD or 0014 if the data format
is binary.
Output disabled by
standby sequence
Alarm mode
3: Lower-limit alarm
2: Upper-limit alarm
1: Upper and lower-limit alarm
8: Absolute-value lower-limit alarm
Section 3-10
Hysteresis
2.0°C
0.5°C
1.0°C
2.0°C