PROFINET and Modbus TCP to SERIAL Gateway

Many standard industrial devices are equipped with serial interfaces, with Modbus RTU as a commonly used serial protocol. Using the EJ1N-HFU-ETN Ethernet to serial gateway, these serial devices can be included in a Profinet or Modbus TCP network without the need to add control with serial interfaces and/or install long wires.

Originally, the EJIN-HFU-ETN gateway was designed for the CelciuX temperature controller to operate with an Ethernet network as the EJ1N-EDU endplate contains the serial network connection which would normally be used to connect via Modbus RTU to other devices. An example is the E5_c PID controllers or the MX2 (or JX, RX and SX) Omron inverters. When a serial multi-location network is used, these units can be placed in series with the gateway.

The gateway is equipped with a built-in switch with three RJ45 Ethernet ports. Besides a link to the controller, it is also possible to connect other Ethernet devices, such as an HMI unit, or a PC to access the control of the installation.

The gateway is included in a PROFINET network, you can use the flexible deployment of standard GSDML files. In your PROFINET tool it is then possible to easily convert Modbus RTU to PROFINET and vice versa. You set the parameters of the used serial devices to your control these should be copied, and which parameters from your controller to the devices in the field must be written. Then the data through the normal cyclical PROFINET communication with shared control.

Since the Ethernet Modbus TCP variant of the Modbus RTU serial protocol is Modbus TCP mode, no parameter conversion is necessary. In this mode the Modbus TCP sends commands to the devices to read and Ethernet Modbus TCP gateway converts the command into the correct serial Modbus RTU command. If you are using an Omron PROFINET unit, it is possible to also use Modbus TCP messages. Intermittent data that is required can also be easily exchanged via Modbus TCP