< 8. Appendix>
8-1
TI 34M6A82-01E
2nd Edition : Nov. 1, 2002-00
8. Appendix
8.1 Special Relay (M)
Special relays have specific functions such as indicating operation and error states of
the CPU.
Program mainly use the special relays as contact a or contact b.
Block Run Status
Block run status relays indicate which block is running when the CPU executes specified
blocks.
Relay M001 corresponds to block 1, M002 to block 2 and so on.
Table
Block Run Status
Item
Block run status
Sequence CPU module
Number
Name
Value
Description
F3SP05, F3SP08, F3SP21
M0001 to M0032
M0001 to M0032
F3SP25, F3SP35
F3SP28, F3SP38
F3SP53, F3SP58, F3SP59
M2001 to M3024
Block n Run
status relay
ON: Running
OFF: Stopped
Indicates whether block n is running
or stopped when the CPU executes
specified blocks.
Note: Run status relays for blocks 1 to 32 are M0001 to M0032 and M2001 to M2032 (M0001 to M0032 and M2001 to
M2032 have identical values), and those for blocks 33 to 1024 are M2033 to M3024.
CAUTION
Do not write to special relays that are not designated as write-enabled including relays
that are not listed in the above table (e.g. M067 to M128) because they are used by the
CPU module system. If you write to these relays inadvertently, an operation might stop.
(Forced Set/Reset in debug mode is also not allowed)
CAUTION
Do not specify an index-modified special relay as an output destination. Otherwise an
instruction processing error will occur during execution.
CAUTION
Do not specify special relays as output destinations in continuous transfer ladder
instructions and table output ladder instructions. Otherwise, an instruction processing
error will occur during execution.
Continuous transfer instructions: BMOV instruction, BEST instruction,
SMOV instruction, etc.
Table output instructions:
ULOGR instruction, FIFWR instruction, etc.