The leader in industrial automation and control solutions

How do I address multiple devices using the Modbus TCP/IP Gateway function?

To address multiple devices, using the Modbus TCP/IP Gateway function: 1. Select the table for the mapped device. 2. Click the “Settings…” button at the bottom of the Address Mapping Table window. 3. Specify the mapped device address in the Table Settings window. Follow Technical Note 5099 “Using the Modbus Gateway” for step-by-step instructions.

Can the HMC be configured as a Modbus TCP master and a slave at the same time?

Yes, the HMC can be configured as a Modbus TCP Master on COM3 and still retain the default Modbus TCP Slave configuration.

You must choose one or the other between master and slave for Modbus RTU, but Modbus TCP can be both simultaneously thanks to Ethernet. As a master (client) you can read Modbus data from, or write Modbus data to, other Modbus TCP devices.

Define Modbus TCP / IP

Modbus TCP/IP (also Modbus-TCP) is simply the Modbus RTU protocol with a TCP interface that runs on Ethernet. The Modbus messaging structure is the application protocol that defines the rules for organizing and interpreting the data independent of the data transmission medium.