Areva MiCOM P225, Technical Manual

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Communication P225/EN CT/B11
MiCOM P225 Page 9/52
1.6 Modbus request definition used to retrieve the fault records
Two ways can be followed to retrieve a fault record :
−
Send a request to retrieve the oldest non-acknowledge fault record.
−
Send a request to retrieve a dedicated fault record.
1.6.1 Request to retrieve the oldest non-acknowledge fault record
Slave number Function code Word address Word number CRC
xx 03h 3Eh 00 00 10h xx............xx
NOTA : On fault retrieval, two possibilities exist regarding the fault record
acknowledgement:
- a) Automatic fault record acknowledgement on event retrieval.
- b) Non automatic fault record acknowledgement on event retrieval.
a) Automatic fault record acknowledgement on fault retrieval :
The bit12 of the remote order frame (format F9 – mapping address 0400h) shall be set to 0.
On fault retrieval, this fault record is acknowledged.
b) Non automatic fault record acknowledgement on fault retrieval :
The bit12 of the remote order frame (format F9 – mapping address 0400h) shall be set to 1.
On fault retrieval, this fault record is not acknowledged.
To acknowledge this fault, an other remote order shall be sent to the relay. The bit 14 of this
frame (format F9 – mapping address 0400h) shall be set to 1.
1.6.2 Request to retrieve a dedicated fault record
Slave number Function code Word address Word number CRC
xx 03h Refer to mapping 00 10h xx............xx
NOTA : This fault value retrieval does not acknowledge this fault record.