Configuring Fields: Modbus

Configuring Fields: Modbus

When a gateway is running Edge Lite and connected to a Zoho IoT application, you can remotely push configurations for devices that communicate to the gateway using the Modbus protocol. Based on the Modbus communication type, the application provides different fields for configuration.

Modbus  RTU

If the communication is via Modbus RTU, you can configure the RS485 port settings and Modbus registry mapping of the connected Modbus device along with the following details.

RS485 Port Settings

Serial Port Name
Identifies the physical or virtual serial port used by the gateway.
Baud Rate
Defines the communication speed between the gateway and Modbus devices, commonly 9600, 19200, or 115200 bps. Both gateway and Modbus device must use the same baud rate.

Parity
Adds an error-checking mechanism.
Data Bit
Number of data bits transmitted per character.
Stop Bit
Indicates the end of a character. Usually 1 or 2 stops bits, depending on the device requirements.

Device Details

Product
The device product representing the peripheral device. The Modbus registry mapping of this device product will be sent to the gateway.
Name
An tag to identify the Modbus device.
Slave ID
The unique Modbus address of the Modbus device. This ensures the gateway communicates with the correct device on the RS485 bus.
Edge Key
A unique key used to identify data from the correct device in the JSON payload. The parameter value for the selected modbus device is appended under this edge key in the payload.

Timeout
The maximum time, in milliseconds, the gateway waits for a response from the device before considering the request failed.

Serial Port 

Device
Port
TRB145
dev/ttyHS0
TRB245
dev/ttyUSB0
TRB246
dev/ttyS1
TRB255
dev/ttyUSB0
RUT956
dev/ttyS1
AG207
dev/ttyUSB1
AG702
dev/ttyUSB1

Modbus TCP & Modbus RTU over TCP 

If the communication is via Modbus TCP or Modbus RTU over TCP, you can configure the Modbus registry mapping of the connected Modbus device and the following details.

Product
The device product representing the peripheral device. The Modbus registry mapping of this device product will be sent to the gateway.
Name
An tag to identify the Modbus device.
Slave ID
The unique Modbus address of the Modbus device. This ensures the gateway communicates with the correct device on the network.

IP Address
The network address of the Modbus device. This allows the gateway to locate and connect to the device over TCP/IP. It must match the static or assigned IP of the peripheral device.

Port
The communication port number on which the Modbus device is listening.
Edge Key
A unique key used to identify data from the correct device in the JSON payload. The parameter value for the selected modbus device is appended under this edge key in the payload.

Timeout
The maximum time, in milliseconds, the gateway waits for a response from the device before considering the request failed.