ModbusTcpGateway

ModbusTcpGateway is the base container for one or more ModbusTcpGatewayDevice components. This network-level component specifies the TCP/IP address and port used to connect to the Modbus TCP/serial gateway, which has Modbus serial devices (typically Modbus RTU, via RS-485) on its far side. Those devices are represented by its child ModbusTcpGatewayDevices

Figure 28. ModbusTcpGateway property sheet

The ModbusTcpGateway has the standard collection of network components, such as for status, health, monitor, tuning policies, and poll scheduler. Other ModbusTcpGateway properties such as Retry Count, Response Timeout, and Max Fails Until Device Down are typically left at defaults, unless particular reasons dictate the change.

You access these properties by expanding Drivers > ModbusTcpNetwork > ModbusTcpDevice and double-clicking theModbusTcpGateway container in the Nav tree.

Property	Value	Description
Float Byte Order	drop-down list	Specifies the byte-order used to assemble or receive floating-point (32-bit) values in messages. Choices reflect two alternate methods, where numerals 0, 1, 2, and 3 represent the least significant byte to most significant byte: Order3210 – Most significant byte first, or big-endian, it is the default. Order1032 – Bytes transmitted in a 1,0,3,2 order, or little–endian.
Long Byte Order	drop-down list	Specifies the byte-order used to assemble or receive long integer (32-bit) values in messages. Choices reflect two alternate methods, where numerals 0, 1, 2, and 3 represent the least significant byte to most significant byte: Order3210 - Most significant byte first, or big-endian, it is the default. Order1032 - Bytes transmitted in a 1,0,3,2 order, or little-endian. NOTE: Float or long values received in incorrect byte order may appear abnormally big, or not at all.
Use Force Multiple Coil	`true` or `false` (default)	Specifies whether to use function code 15 (Force Multiple Coils) instead of function code 05 (Force Single Coil) when writing to coils. The default is `false`, where function code 05 (Force Single Coil) is used. This property depends on the Modbus function codes supported by child devices, which (if available) provide alternative options in Modbus messaging. Function code 15 support (Preset Multiple Coils) is available in devices (true or false). The default is `false`, where function code `Preset Single Coil` is in place.
Use Preset Multiple Register	`true` or `false` (default)	Specifies whether to use function code 16 (`Preset Multiple Registers`) instead of function code 06 (`Preset Single Register`) when writing to registers. The default is `false`, where function code 06 (`Preset Single Register`) is used. This property depends on the Modbus function codes supported by child devices, which (if available) provide alternative options in Modbus messaging. Function code 16 support (`Preset Multiple Registers`) is available in devices (`true` or `false`). The default is `false`, where function code `Preset Single Register` is in place.
Ip Address	IP address	Identifies a device, which is connected to a network that uses the Internet Protocol for communication.
Port	number (defaults to 502)	Specifies the TCP port used by Modbus message transactions. Leave at the default (502) unless the TCP/Ethernet-side of the Modbus TCP/serial gateway uses another TCP port.

ModbusTcpGateway

Figure 28. ModbusTcpGateway property sheet

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