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Hello,
I would be grateful for any help with connecting 4-wire Modbus RTU slaves to a 2-wire master controller. The controller is Honeywell Eagle CLEA2000B31, with Modbus RS-485-1 connectors labelled simply + and -. The slave devices would be Mitsubishi FR-D700 series inverters, equipped with RJ45 connector.
The controllers' (CLEA2000B31) communication manual includes diagrams of connecting 2-wire slaves to the bus, but no mention of 4-wire connections. The manual is located here:
http://products.centraline.com/en/pdf/eagle-comm-en2z1002-ge51r0117.pdf
The inverters' (FR-D700 series) manual states the bus would be "Conforming standard: EIA-485 (RS-485)" and "Transmission form: Multidrop link"
The inverter manual is located here (a large document with 300+ pages):
http://dl.mitsubishielectric.com/dl/fa/document/manual/inv/ib0600366eng/ib0600366engg.pdf
Manual page 181 (.pdf file page number or page 179 as "printed") lists the RJ45 connector pin numbering, with pins 3-6 being relevant. From modbus.org specs I understood that for 2-wire communication pins 4 and 5 are used.
I thought this kind of connection would require a converter device, but the inverter manual page 183 does include the following detail:
"Two-wire type connection -
If the computer is 2-wire type, a connection from the inverter can be changed to 2-wire type by passing wires across reception terminals and transmission terminals of the PU connector pin."
So the wires SDA and RDA should be connected, and SDB with RDB. But does anyone here have experience with Honeywell controller and 4-wire Modbus devices, is a converter required? And if so, is there a recommendation for a DIN-rail mounted one?
I would be grateful for any help with connecting 4-wire Modbus RTU slaves to a 2-wire master controller. The controller is Honeywell Eagle CLEA2000B31, with Modbus RS-485-1 connectors labelled simply + and -. The slave devices would be Mitsubishi FR-D700 series inverters, equipped with RJ45 connector.
The controllers' (CLEA2000B31) communication manual includes diagrams of connecting 2-wire slaves to the bus, but no mention of 4-wire connections. The manual is located here:
http://products.centraline.com/en/pdf/eagle-comm-en2z1002-ge51r0117.pdf
The inverters' (FR-D700 series) manual states the bus would be "Conforming standard: EIA-485 (RS-485)" and "Transmission form: Multidrop link"
The inverter manual is located here (a large document with 300+ pages):
http://dl.mitsubishielectric.com/dl/fa/document/manual/inv/ib0600366eng/ib0600366engg.pdf
Manual page 181 (.pdf file page number or page 179 as "printed") lists the RJ45 connector pin numbering, with pins 3-6 being relevant. From modbus.org specs I understood that for 2-wire communication pins 4 and 5 are used.
I thought this kind of connection would require a converter device, but the inverter manual page 183 does include the following detail:
"Two-wire type connection -
If the computer is 2-wire type, a connection from the inverter can be changed to 2-wire type by passing wires across reception terminals and transmission terminals of the PU connector pin."
So the wires SDA and RDA should be connected, and SDB with RDB. But does anyone here have experience with Honeywell controller and 4-wire Modbus devices, is a converter required? And if so, is there a recommendation for a DIN-rail mounted one?