Modbus

1min

Note: By default, the Modbus drivers monitor holding address 0 for connection status. If the Modbus device does not have holding address 0, then it will not show the "connected" status. You will still be able to read data from the device.
Here are the major differences for the Modbus drivers:
Driver
Use
﻿Enron Modbus﻿﻿
Serial connection or TCP connection to a Modbus device
﻿Modbus ASCII﻿﻿
﻿Modbus ASCII (Gen1)﻿﻿
﻿Modbus ASCII Advanced﻿﻿
Serial connection to a device using Modbus ASCII
﻿Modbus RTU﻿﻿
﻿Modbus RTU (Gen1)﻿﻿
﻿Modbus RTU Advanced﻿﻿
﻿Modbus RTU-Offset (Gen1)﻿﻿
Serial connection to a device using Modbus RTU.
The Gen2 driver has an option for zero-based addressing and therefore replaces both Gen1 RTU drivers.
﻿Modbus RTU over TCP﻿﻿
TCP connection to a Modbus server which has one or more Modbus RTU connections
﻿Modbus TCP﻿﻿
﻿Modbus TCP (Gen1)﻿﻿
﻿Modbus TCP-Offset (Gen1)﻿﻿
TCP connection to a Modbus device.
The Gen2 driver has an option for zero-based addressing and therefore replaces both Gen1 TCP drivers.
﻿Modbus UDP﻿﻿
﻿Modbus UDP (Gen1)﻿﻿
UDP connection to a Modbus device
﻿

Driver	Use
Enron Modbus	Serial connection or TCP connection to a Modbus device
Modbus ASCII Modbus ASCII (Gen1) Modbus ASCII Advanced	Serial connection to a device using Modbus ASCII
Modbus RTU Modbus RTU (Gen1) Modbus RTU Advanced Modbus RTU-Offset (Gen1)	Serial connection to a device using Modbus RTU. The Gen2 driver has an option for zero-based addressing and therefore replaces both Gen1 RTU drivers.
Modbus RTU over TCP	TCP connection to a Modbus server which has one or more Modbus RTU connections
Modbus TCP Modbus TCP (Gen1) Modbus TCP-Offset (Gen1)	TCP connection to a Modbus device. The Gen2 driver has an option for zero-based addressing and therefore replaces both Gen1 TCP drivers.
Modbus UDP Modbus UDP (Gen1)	UDP connection to a Modbus device

Mitsubishi QJ71E71

Modbus ASCII (Gen1)