This section provides an overview on how to physically connect with various third party devices. The IG21 and IG61 can communicate with third party devices from other manufacturers via Modbus RTU, Modbus TCP, Modbus ASCII, Ethernet IP, MQTT, and OPC-UA. This enables the IG and Samsara cloud platform to be able to read and write data from other PLCs, machines, and sensors related to controlling a process.
The physical connection to these third party devices are outlined in the next sections. Cloud configuration and setting up third party devices within the Samsara dashboard is covered in in our article on Configuring Third Party Devices.
Serial is a communication media which allows the Industrial Gateway (IG21/IG61) to connect to an external device over an RS485 or RS232 connection. The diagram shows how to properly wire the IG21 to a third party device over serial connection.
Supported serial protocols
As a rule of thumb, always follow polarity (+/-) associated with wires.
Ethernet is a communication media which allows the Industrial Gateway (IG21/IG61) to connect to an external device using an ethernet cable with an RJ45 connection. The gateway can be connected to a single third party device via ethernet directly or using an ethernet switch. The diagram below shows how to properly wire the IG21 to a third party device over Ethernet.