ScreenMaster RVG200
Paperless recorder
7 Configuration
126
OI/RVG200-EN
7.10.10 RS485 (MODBUS) communications
Refer to Appendix B, page 149 for further information on using the MODBUS link.
Note.
This Section is applicable only if the optional MODBUS module is fitted.
RS485
Protocol
Select the MODBUS protocol required.
MODBUS Slave
MODBUS Master
–
–
recorder operates as a MODBUS Slave
recorder operates as a MODBUS Master
Type
Set according to the number of transmission wires connected to the
recorder.
4-wire
2-wire
Baud rate
Set the Baud rate used by the host system:
1200
,
2400
,
4800
,
9600
,
19200
,
38400
,
115200
.
Parity
Set the Parity used by the host system:
None
,
Odd
,
Even
.
Address
Note.
Displayed only if
Protocol
is set to
MODBUS Slave
.
Set a unique MODBUS Address (between 1 and 247) to enable the host
system to identify the recorder on a MODBUS link.
Note.
Maximum 32 slaves per loop.
Note.
The remaining parameters are displayed only if
Protocol
is set to
MODBUS Master
.
Poll rate
Set the poll rate in milliseconds – minimum 0, maximum 3600000.
Poll fail limit
Set the number of successive polls permitted to fail before the data is
marked as a failed input – minimum 0, maximum 4.
Poll rate interval
Set the time interval between individual messages within a poll.
Response Timeout
Set the timeout time in milliseconds for a single poll – minimum 0,
maximum 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.