Special Relay Sm, Special Register Sd - Mitsubishi Electric M800VW Series Programming Manual

M800V/M80V Series PLC Programming Manual (1/2)
4 Explanation of Devices
4.4 Detailed Explanation of Devices

4.4.5 Special Relay SM, Special Register SD

 Special relay is the relay whose application is fixed. (i.e. Carry flag of operation result, display request signal to the setting
display device, etc.) Do not use the currently unused area from SM0 to SM2047 as the temporary memory.
 Special register SD is the data register whose application is fixed. (i.e. 1-second counter)
Do not use the currently unused area from SD0 to SD2047 as the temporary memory.
Special relay SM, Special register SD
 It will be cleared when the power is turned OFF.
 There is no limit in the number that can be used in the program.
 The relay and register No. are expressed with a decimal.
 Some of the main relays and registers whose applications are fixed are listed below.
Special relay
Device Name
PLC error
SM0
Carry flag
SM12
H/W alarm (Temperature rise
SM16
detection)
SM17 H/W alarm (DIO 24V illegal)
H/W alarm (Power supply er-
SM18
ror)
SM64 ATC display request flag
Tool life management setting
SM65
lock
SM70 Key I/F related
SM71 In ATC rotation
Always ON
SM400
Always OFF
SM401
After RUN, turned ON by only
1 scan
SM402
(Medium-speed ladder)
After RUN, turned OFF by
only 1 scan
SM403
(Medium-speed ladder)
After RUN, turned ON by only
1 scan
SM404
(High-speed ladder)
After RUN, turned OFF by
only 1 scan
SM405
(High-speed ladder)
IB-1501667-B
Operation
OFF: No error  Turned ON when the PLC alarm (illegal PLC)
ON: Error has occurred.
 Reset is done by STOP -> RUN.
OFF: Carry OFF Carry flag used during function instruction.
ON: Carry ON
OFF: No alarm Used in some machine types.
ON: Alarm Refer to "PLC Interface Manual", etc. for details.
Refer to PLC I/F Manual, etc. Used in some machine types.
for details. Refer to "PLC Interface Manual", etc. for details.
 Always ON
ON
OFF
 Always OFF
ON
OFF
 After RUN, turned ON by only 1 scan
ON
 OFF during STOP.
1 scan
OFF
 This contact can be used only in the medium-
speed ladder.
 After RUN, turned OFF by only 1 scan
ON
 OFF during STOP.
1 scan
OFF
 This contact can be used only in the medium-
speed ladder.
 After RUN, turned ON by only 1 scan
ON
 OFF during STOP.
1 scan
OFF
 This contact can be used only in the high-
speed ladder.
 After RUN, turned OFF by only 1 scan
ON
 OFF during STOP.
1 scan
OFF
 This contact can be used only in the high-
speed ladder.
36
Setting side
Details
(Set time)
System side
(Error)
System side
(State
change)
System side
(State
change)
System side
(State
change)
System side
(Every time
END)
System side
(Every time
END)
System side
(Every time
END)
System side
(Every time
END)
System side
(Every time
END)
System side
(Every time
END)