MITSUBISHI ELECTRIC 700 Series - Manual (Page 107)

102
Operation Error
3.22 Operation Error
When a basic instruction is used, an operation error will occur in the following
case.
(a) If any error described in the description of the corresponding instruction
occurs.
(1) Error processing
If an operation error occurred at execution of a basic instruction, the error flag
turns on and the error step number is stored into the error step storage register.
1) D9011 stores the step number of the instruction where an operation error occurred
when M9011 turned from OFF to ON. Therefore, D9011 data does not change if
M9011 remains on.
2) To reset M9011 and D9011, program as shown below.
Fig 3.28 Special Relay and Register Resetting Ladder
3) Whether sequence processing will be stopped or continued at occurrence of an
operation error can be selected by built-in PLC function parameter setting. Refer to
page 94 for details.
POINT
Note that if the device designation range is outside the corresponding device
range, an operation error does not occur and data is written to other than the
specified device.
Error flag
M9010 ... Turns on at an operation error and turns off if the next basic
instruction is normal.
M9011.... Turns on at the first operation error.
Error step
storage register
D9010.... Stores the first step number of the instruction where an operation
error occurred.
D9011 .... Stores the first step number of the instruction where an operation
error occurred first.
M50 to M65 are the targets, but actual
setting range is M0 to M63, and error
occurs since M64 and M65 do not exist.
Resets (turns off) M9011.
Resets D9011.
(Clears D9011 to 0.)
Reset command
Reset command