Mitsubishi 00JCPU User Manual page 387

9.2.4 Latch relay (L)
(1) Definition
The latch relay (L) is a device for auxiliary relays that can be latched inside the CPU module.
Latch relay data are retained by batteries in the CPU module during power failure.
Operation results (on/off information) immediately before the following will be also retained.
• Powering off and then on the CPU module
• Resetting the CPU module
(2) Latch relay clear
The latch relay is turned off by the latch clear operation. (
However, the latch relay set in "Latch (2) start/end" in the Device tab of the PLC parameter dialog box cannot be
turned off even if the RESET/L.CLR switch
(3) Allowable number of normally open or closed contacts
There are no restrictions on the number of normally open or closed contacts used in a program, as long as the
program capacity is not exceeded.
X0
L0
L0
X1
X2 L0
Note1
Note9.1
Basic
For the Basic model QCPU, switch operation is not allowed to clear the latch.
or the remote latch clear function is
Note9.1
No restrictions on the quantity used.
M0 is set to on when L0 turns on from off.
SET L0
Latch relay (L0) can be set to on only for
use inside the CPU module, and not for
output to the outside.
K20
T0
Y20
The on/off information of L0 is output from the
output module to the external device.
L100
L2047
Figure 9.10 Latch relay
Section 3.7)
used.Note1
CHAPTER9 DEVICES
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