sylvac PLC Mode D'emploi page 57

A. Annexe MODBUS Protocol
Default RS485 configuration for Modbus protocol :
128'000bauds
8 bits
Even parity
1 stop
D
A.1 Modbus transactions
The master issues a Query Modbus frame on the bus. The addressed salve answers (except for broadcast requests) with a Response Modbus
frame. The salve answer can be a correct answer or an Exception in case of error.
For better data throughput, Sylvac modules always use the RTU transmission mode. For more details on Modbus protocol, refer to the
MODBUS Application Protocol.
http://www.modbus.org/docs/PI_MBUS_300.pdf
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