Equivalent Logic in PLC Programming

If you understand basic electrical diagrams, it is much easier to understand ladder logic.

In fact, that was the whole idea behind ladder logic. It was supposed to look, and work, like real electrical circuits Read more

RSLogix 500 Addressing in an Allen-Bradley PLC

There are a number of addressing schemes used by PLC manufacturers. Let’s take a quick look at how memory locations (including hardware I/O) are accessed with RSLogix 500. Along the way, I will define some terms. Read more

RSLogix 5000 “Serial” Logic

RSLogix 5000 allows the use of “serial” logic that does not conform to traditional, electrical ladder logic.

For example, both of the rungs shown below are valid in RSLogix 5000. Read more

Setting up the Analog Input Card in RSLogix 5000

Let’s assume that the output of our scales has been calibrated for 0-10 VDC. Zero volts equals 0 pounds, and 10 volts equals 2000 pounds.

Now we know the signal type is DC voltage, the range is 0-10 and the engineering units are pounds. Read more

Ladder Logic and the Dialect of PLCs

Ladder logic is a programming language, like Visual Basic or C. When you learn any language, it is always important to understand the basic terms.

If you are just getting started, here are a few terms you should know. These apply to any PLC. Read more