2-3
Remark: During power up or changing operation mode from STOP→RUN, all contents in non-retentive relays or
registers will be cleared to 0; the retentive relays or registers will remain the same state as before.
Relay No. Function Description
1. Stop, Prohibited Control
M1912 Emergency Stop control y If ON, PLC will be stopped (but not enter STOP mode) and all
outputs OFF.
This bit will be cleared when power up or changing operation
mode from STOP→RUN.
M1913 Disable external outputs control y All external outputs are turn off but the
status of Y0~Y255 inside the PLC will not be affected.
M2001 Disable/Enable status retentive control yIf M2001 is 0 or enabled, the Disable/Enable status of all
contacts will be reset to enable during power up or changing
operation mode from STOP→RUN.
yIf M2001 is disabled and force ON, the Disable/Enable status &
ON/OFF state of all contacts will remain as before during power
up or changing operation mode from STOP→RUN.
While testing, it may disable and force ON M2001 to keep the
ON/OFF state of disabled contacts, but don’t forget to enable
the M2001 after testing.
2. CLEAR Control
M1914 Clear Non-Retentive Relays y Cleared When at 1
M1915 Clear Retentive Relays y Cleared When at 1
M1916 Clear Non-Retentive Registers y Cleared When at 1
M1917 Clear Retentive Registers y Cleared When at 1
M1918 Master Control (MC) Selection y If 0, the pulse activated functions within the master control loop
will only be executed once at first 0→1 of master control loop.
If 1, the pulse activated functions within the master control loop
will be executed every time while changing 0→1 of master
control loop.
M1919 Function output control yIf 0, the functional outputs of some function instructions will
memory the output state, even these instructions not been
executed.
If 1, the functional output of some function instructions without
the memory ability.
※ M1918/M1919 can be set to 0 or 1 at will around the whole program to meet the control requirements.
2.3 Special Relay Details