Mitsubishi 00JCPU User Manual page 386

9.2.3 Internal relay (M)
(1) Definition
The internal relay (M) is a device for auxiliary relays used in the CPU module.
All of the internal relay are set to off in the following cases:
• When the CPU module is powered off and then on
• When the CPU module is reset
• When latch clear is executed (
(2) Latch (data retention during power failure)
The internal relay cannot be latched.
(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
M0
X1 M0
X2 M0
(4) Method for external output
The output (Y) is used to output sequence program operation results to external devices.
Use the latch relay (L) when latch (data retention during power failure) is required (
9 - 11
Section 6.3)
No restrictions on the quantity used.
M0 is set to on when X0 turns on from off.
SET M0
Internal relay (M0) 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 M0 is output from the
output module to the external device.
M100
M2047
Figure 9.9 Internal relay (M) used in a program
Section 9.2.4)