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If the RS485 Modbus adapter is one of the two ending station on the
communication line put the load termination switch in the 'ON 'position. If not,
put it in the 'OFF 'position.
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Make sure all other Modbus stations (master and slaves) are properly connected
Apply power on the controller
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Enter the MODBUS menu under:
COMMUNICATION - I/O CONFIGURATION – COM. SETTINGS – MODBUS
Choose a slave address (the address must be unused in the Modbus network
·
it is inserted in)
·
Select the right communication speed (baud rate)
·
Select the right parity checking
·
Select the right number of stop bits
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The Modbus slave is now ready to receive Modbus queries from the Modbus
master and to send Modbus response accordingly
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If something goes wrong, see the trouble shooting section hereafter
4.6 To set the COMMUNICATION LOCK parameter
If the RVT's parameters should be changed only from the Modbus network, set the
Communication lock item as locked. It can be found under the following menu:
COMMUNICATION - I/O CONFIGURATION – COM. SETTINGS
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Set the Communication lock parameter to 'Locked'
4.7 To test the communication
Depending on the way the controller is connected to the Modbus network, different
ways of testing may be chosen.
The user can find much application on the internet to scan Modbus devices and test
communication.
In case of problem, please refer to the troubleshooting paragraph.
12 RS485 Modbus adapter ç RS485