gary_and

Hi erveryone, i'm new to the world of plc but very eager to learn. i'm currently working on a project that requires a vacuum pump to be driven at 4 different speeds. The pump is hooked up to a VFD and what i was wondering is it possible to create ladder code to make DA1I send different 4-20mA signal to the VFD to get the different speeds? This is my first project and its probably a little over my head but i'm keen to give it a go. thanks