Appendix 1 special soft device list
ID Function Description
M8020 Zero The plus/minus operation result is 0
M8021
Borrow “borrow” occurs in minus operation
M8022
Carry
When carry occurs in plus operation or overflow
occurs in bit shift operation
M8023
M8026 RAMP Mode
M8029
ID Function Description
M8030 PLC initializing
M8031
Non-retentive register reset
M8032
Retentive register reset
When driving this M, ON/OFF mapping memory of
Y, M, S, TC and the current values of T, C, D are all
reset to be 0
M8033
Registers keep stopping
When PLC changes from RUN to STOP, leave all
content in mapping registers and data registers
M8034
All output forbidden Set PC’s all external contacts to be OFF status
M8038
Parameter setting Set communication parameters flag
ID Function Description
M8041
M8045 All output reset forbidden
When shifting the mode, all outputs
functions are forbidden
M8046 STL status activate
When M8047 activating, act when any device of
S0~S999 turns to be ON
Flag (M8020-M8029)
PC Mode (M8030-M8038)
Stepping Ladder (M8041-M8046)