Another “Swiss Army Knife” for PLC Networks : Raspberry Pi 3

Say bye bye to the laptop.  It is annoying when we need to troubleshoot or to replace Allen Bradley ControlLogix CPUs or modules  and we don’t know what  the model and revision is. Another case is when we have to do verification on Endress Hauser Promag 400 or other Field devices  and we forget where the laptop is or  with…

“Poorman” PLC I/O board

Most process or manufacturing plants have PLC control panels which get inputs from variety buttons, switches and to activate relays, solenoid valves etc.  In many cases, they use 24V DC power supply for PLC CPUs and/or for I/O modules. For 24V DC relays, they  can drive directly to 24V DC solenoid valves, coils etc. To activate higher voltage such as …

Convert legacy control panel into LCD alarm and warning system with Arduino.

In the old days, We used to have electronic controller modules or PLCs which give warning or alarms on the panel by turning several light indicators  on or off. To understand these signals we have to refer their operation manual/books to interpret these messages. For example there are three indicators on the panel which has light A(lA), light B(lB) and…