Glen @ bikerglen.com writes:
The RS-422 / RS-485 shield is an open source shield designed to add RS-422 and RS-485 communication capabilities to the ProductivityOpen family of open-source programmable logic controllers (PLC’s) from Automation Direct. It’s loosely based on the Arduino MKR RS-485 shield but updated to use an ADM2582E 3.3 V isolated RS-485 transceiver from Analog Devices. The completed shield fits inside the P1AM-PROTO prototyping enclosure.
If you’re not familiar with the expansion capabilities of the Automation Direct P1AM-100 Open-Source PLC, now would be a good time to read my previous blog post on the subject. For this project, I’m going to create a new design using the Eagle PCB library symbol created in that post then add an isolated RS-422 / RS-485 transceiver and its support circuitry.