Omron Sysmac CJ Series, Operation Manual

Page: 83 / 117

60
Using the Alarm Output Function Section 3-10
• Changing D (The Derivative Time)
3-10 Using the Alarm Output Function
This section explains the alarm modes, standby sequence, and alarm values.
3-10-1 Setting the Alarm Mode
There are two alarm outputs for each loop and any of the following nine alarm
modes can be selected for each alarm’s operation.
To use the alarm output function, set the corresponding alarm mode setting in
the Initialization Data words allocated in the DM Area to the Temperature Con-
trol Unit.
Note If the alarm mode setting is changed, the new setting will not become effective
until the power is turned ON again or the Unit is restarted. Always turn the
power supply OFF and ON again or restart the Unit after changing the alarm
mode.
Alarm Modes
In the following diagrams, the “X” indicates the alarm SV. The initial value is
“0.”
Increasing D Overshooting, undershooting,
and the set time are reduced,
but hunting will occur from small
changes in the system itself.
Decreasing D Overshooting and undershoot-
ing are increased. It takes time
to return to the SP.
SP
SP
Setting Alarm mode Alarm output function
Alarm SV (X) is positive Alarm SV (X) is negative
0 No alarm Output OFF
1 Upper and lower-limit alarm Always ON
2 Upper-limit alarm
3 Lower-limit alarm
4 Upper and lower-limit range
alarm Always OFF
5 Upper and lower-limit alarm
with standby sequence Always OFF
6 Upper-limit alarm with standby
sequence
ON
OFF
X X
SP
ON
OFF
X
SP
ON
OFF
X
SP
ON
OFF
X
SP
ON
OFF
X
SP
ON
OFF
X
SP
X
ON
OFF
X
SP
X
ON
OFF
X
SP
ON
OFF
X
SP