Rs485 (Modbus™) Communications - ABB SM2000 User Manual

Advanced Videographic Recorder
SM2000
4.4.8 RS485 (Modbus™) Communications
Refer to Appendix B, page 110 for further information on using the Modbus link.
IM/SM2000 Issue 11
Select the Modbus protocol required.
Modbus – instrument acts as a Modbus Slave
Modbus Master – instrument acts as a Modbus Master
Set according to the number of transmission wires connected to
the instrument: 4-wire, 2-wire.
Set to the Baud rate used by the host system: 1200, 2400,
4800, 9600, 19200, 38400, 115200.
Set to the Parity used by the host system: None, Odd, Even.
Note. Displayed only if 'Protocol' is set to 'Modbus'.
Set a unique Modbus Address that allows the host system to
identify the instrument on a Modbus link.
Note. Maximum 31 slaves per loop.
Note. Displayed only if 'Protocol' is set to 'Modbus Master'.
Set the poll rate in milliseconds – min. 0, max. 3600000.
Note. Displayed only if 'Protocol' is set to 'Modbus Master'.
Set the number of successive polls permitted to fail before the
data is marked as a failed input – min. 0, max. 4.
Note. Displayed only if 'Protocol' is set to 'Modbus Master'.
Set the timeout time in milliseconds for a single poll – min. 0,
max. 60000.
Note. If any RTU devices are polled, set a response time that is
long enough to allow for the normal turn around time from these
devices. The configuration allows for only one setting for all
devices connected to the network.
4 CONFIGURATION
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