ModbusSlaveNetwork

This component configures a Modbus slave network. A slave-type Modbus network allows the station to appear as one or more virtual Modbus slave devices, each providing some number of Modbus virtual data items. On the Modbus network the station simply waits for (and responds to) client requests from a master device. All proxy points are Modbus server types, where point polling monitors for external writes to some proxy points. Data exchange with the Modbus master occurs in this fashion with proxy points, and in rare cases with reads and writes to server file records (for string data).

Figure 18. ModbusSlaveNetwork property sheet

The ModbusSlaveNetwork has the standard collection of network components, such as for status, health, monitor, tuning policies, and poll scheduler. For more details, refer to the Niagara Drivers Guide.

You can access these properties by double-clicking Driver > ModbusSlaveNetwork 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.
Serial Port Config	additional properties	Refer to Serial Port Config.
Modbus Data Mode	drop-down list (defaults to Rtu)	Selects the type of serial network. `Rtu` (Remote Terminal Unit) `Ascii` (American Standard Code for Information Interchange)
Sniffer Mode	`true` or `false` (default)	Usually left at the default unless there is a particular reason to change it.

Serial Port Config

Specifies the serial port/communications setup required to talk to the attached serial Modbus master.

Figure 19. Serial Port Config properties

In addition to the standard property (Status), these properties are unique to serial port configuration:

Property	Value	Description
Port Name	text (defaults to none)	Configures a name for the current Ethernet port.
Baud Rate	drop-down list (defaults to `Baud9600`)	Defines communication speed in bits per second.
Data Bits	drop-down list (defaults to `Data Bits8`)	Defines the number of bits required to encode a character (a byte).
Stop Bits	drop-down list (defaults to `Stop Bit1`)	Defines the number of bits that indicate the end of a character.
Parity	drop-down list (defaults to `None`)	Defines the odd or even requirement of a transmitted byte of data for the purpose of error detection.
Flow Control Mode	check box	Using the selected Modbus protocol, manages the efficient transmission of data between two devices.