Chapter 14. The RS422/485 communication of GM6-CPUB
14-4
14.4 The status flag
1) Communication error counter flag
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Flag name : _M422_ERR_CNT[n] (Array_Byte Type, n = 0 ~ 31)
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Description
Each byte of the ‘_M422_ERR_CNT[n]’ array indicates how many times
communication errors occurred at the relevant station. For example, the
_M422_ERR_CNT[5] is the error counter of station 5.
2) The error code
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Flag name : _M422_ERR[n] (Array_Byte Type, n = 0 ~ 31)
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Description
0 : No error
1 : Timeout error
2 : NAK
3) Operation mode and error of slave station
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Flag name : _S422_STATE[n] (Array_Byte Type, n = 0 ~ 31)
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Description
Bit 0 : Indicates an error of slave PLC. (0 : No error, 1 : Error occurred)
Bit 1 ~ Bit 3 : Reserved
Bit 4 ~ Bit 7 : Indicates the operation mode of slave PLC
Bit 4 : STOP
Bit 5 : RUN
Bit 6 : PAUSE
Bit 7 : DEBUG
4) The status flag of master station
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Flag name : _M422_STATE (Byte Type, n = 0 ~ 31)
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Description
Bit 0 : Turn on when the CPU module is assigned as master station but it is not B type
(GM6-CPUB)
Bit 1 : Turn on when the master station number of basic parameter setting is duplicated
with one of the slave station numbers of high speed link parameters setting.
Bit 2 : Turn on when the M area of high speed link parameter setting is out of the range.
5) The scan time of RS422/485 communication
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Description
_M422_SCAN_MAX (Time Type) : The maximum scan time
_M422_SCAN_MIN (Time Type) : The minimum scan time
_M422_SCAN_CUR (Time Type) : The current scan time
Scan time : A total time of the processing time of the all parameter settings. (From the execution of the first
parameter setting to the next execution)
Remark