Mitsubishi Electronics QSPCU Manual Do Utilizador

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12.6  Special Relay List

Special relays, SM, are internal relays whose applications are fixed in the programmable 
controller.
For this reason, they cannot be used by sequence programs in the same way as the
normal internal relays.
However, they can be turned ON or OFF as needed in order to control the CPU module
and remote I/O modules.
The heading descriptions in the following special relay lists are shown in Table12.11.

For details on the following items, refer to the following manuals:
 • Networks

 Manuals of each network module

In the program that achieves the safety function, only SM1000 to SM1299 can be 
used.
Special relay other than SM1000 to SM1299 cannot be used in the program that 
achieves the safety function.

Number

• Indicates special register number

Name

• Indicates name of special register

Meaning

• Indicates contents of special register

Explanation

• Discusses contents of special register in more detail

Set by 
(When set)

• Indicates whether the relay is set by the system or user, and, if it is set by the system, when setting is performed.

<Set by>
  S

: Set by system

  U

: Set by user (sequence programs or test operations from GX Developer)

  S/U

: Set by both system and user

<When set>
  Indicated only for registers set by system
  Every END

: Set during every END processing

  Initial

: Set only during initial processing (when power supply is turned ON, or when going from STOP to RUN)

  Status change

: Set only when there is a change in status

  Error

: Set when error occurs

  Instruction execution : Set when instruction is executed
  Request

: Set only when there is a user request (through SM, etc.)