Master devices are designed to control all slave devices on the Modbus.
Most Master devices can be placed between your computer and the slaves. In most situations your computer is the Master device.
In this scenario communication goes through the COM port of the computer.
Modbus RTU/TCP gateway (NITOT)
This small Modbus gateway can work in a local area network as well as in the
global area network. It can transfer data between Modbus RTU and Modbus TCP. It
has several working mode including TCP master and RTU master. Tanks to this, it
is ideal for implementing the Modbus communication over the Internet.
Find out more about the Modbus RTU/TCP gateway
USB to RS485 converters
They allow you to control Modbus devices via one of the COM ports.
This section shows two types of converters: a converter that transmits only data, and another one that
transmits data and voltage through the USB port. They are not exactly Master devices, they just forward electricity.
Select an USB to RS485 converter for your needs
PC or Laptop
It is the most common Master device, since you use it daily and can directly connect it to the Modbus network through the USB port.
PCs are intended to be operated directly by an end user, rather than by a computer expert or technician.
Conventionally, a modern computer consists of at least one processing element, typically a central processing unit (CPU), and some form of memory.