Fetch Comm Event Log (Function 12) - ABB RVT Serie Instrucciones De Instalación Y De Funcionamiento

QUERY
Slave address
Function
Error check field CRC

3.6 Fetch comm event log (function 12)

Returns a status word, the comm event counter (see function 11), the bus message
counter (see function 08 subfunction 11), and a field of event bytes from the slave.
The format of a Fetch comm event log (12) function query is as follows:
QUERY
Slave address
Function
Error check field CRC
The 64 bytes wide Event log buffer is filled with communication events. The most recent
communications event is shown in the Event 0 byte.
Event bytes are stored in the Even log buffer for 4 different reasons.
The bit will be set to logic '1' if the corresponding condition is TRUE.
Slave Modbus Receive Event
This type of event byte is stored by the slave when a query message is received.
It is stored before the slave processes the message.
Bit Contents
0 Not Used
1 Communications Error
2 Not Used
3 Not Used
4 Character Overrun
5 Currently in Listen Only Mode
6 Broadcast Received
7 1
RESPONSE
1 byte Slave address
Function
1 byte
Status word
2 bytes
Event counter
Error check field CRC
RESPONSE
1 byte Slave address
1 byte Function
2 bytes Byte count
Status word
Event counter
Bus message counter
Event log buffer
Error check field CRC
1 byte (echo of master's query)
1 byte (echo of master's query)
2 bytes (0)
2 bytes
2 bytes
1 byte (echo of master's query)
1 byte (echo of master's query)
1 byte
2 bytes (0)
2 bytes
2 bytes
N bytes
2 bytes
RVT communication ç Modbus function codes 17