To see the current number of licensed Modbus devices or available viewLinc device spaces, see Help > About. |
Connecting Modbus Devices
Modbus RTU devices may be connected to your network with a Digi or other Ethernet device, or with a serial cable to connect directly to a viewLinc Device Host. Modbus TCP devices are connected directly to your network with a network cable.
Connecting Modbus devices to your network requires advanced networking expertise. Refer to your Modbus device documentation to complete the installation steps, including installation of required Digi or Ethernet device drivers on the host server, and verification of network connectivity. |
Input and Holding Registers
Modbus devices contain input and holding registers that read and write data using 16-bit or 32-bit wide integers. The data structure used by the Modbus device manufacturer defines the way you will need to configure viewLinc.
The first step is to refer to your Modbus device documentation to determine whether the register format is based on an address (decimal or hexadecimal) or a number. If your device uses the wider 32-bit format, the data format may be higher byte/word first or lower byte/word first.
Register Types | Register Number Ranges | Data format options | |
---|---|---|---|
Coil | 00001-09999 | Boolean / Boolean Inverted | |
Discrete Input | 10001-19999 | Boolean / Boolean Inverted | |
Input Register | 30001-39999 |
|
|
Holding Register | 40001-49999 |
|
Since Modbus device documentation is not standardized, it may provide configuration information in a variety of ways. To learn more about Modbus, useful online resources include: www.modbus.org, and 'How to add a Modbus Device', available from the Tours menu. |