Schneider Electric BM85 manual Routing to Host Based Network Adapters

2.1.2Routing to Host Based Network Adapters

￿or host based network adapters, the byte following the adapter's network node address specifies a task number (1 ... 8) to which the message is assigned. Subsequent bytes are not checked by the adapter, and are available for custom use to the application - for example, for message counts or status information.

2.1.3Routing to BM85 Bridge/Multiplexers

Routing to Serial Ports on BM85 Programmable Models

￿or the programmable models, the user application stored in the BM85 defines the addressing between Modbus Plus and the serial ports.

Routing to a Single Slave Device on BM85 Modbus Models

￿or a single slave device at a Modbus port, two bytes are used to address the device. The next-to-last non-zero byte addresses the BM85 node (1 ... 64). The last non-zero byte specifies the Modbus port (1 ... 4), and therefore specifies the single slave device.

￿igure 5 shows an example of routing to a single slave device.

BP85	BM85	BM85	ZERO	ZERO
ADDRESS	ADDRESS	PORT
(1 ... 64)	(1 ... 64)	(1 ... 4)

Figure 5 Modbus Plus Routing to Single Modbus Slave

Routing to a Networked Slave Device on BM85 Modbus Models

￿or a slave device on a Modbus network at a Modbus port, three bytes are used to address the device. The third byte from the last non-zero byte addresses the BM85 node (1 ... 64). The next-to-last non-zero byte specifies the Modbus port (1 ... 4). The last non-zero byte specifies the Modbus address of the slave device (1 ... 247).

￿igure 6 shows an example of routing to a networked slave device.

BP85		BM85		BM85		SLAVE		ZERO
ADDRESS		ADDRESS		PORT		ADDRESS
(1 ...	64)	(1 ...	64)	(1 ...	4)	(1 ...	247)

Figure 6 Modbus Plus Routing to Networked Modbus Slave

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Device Addressing and Message Routing 19