Video: How to Program a TON Timer in RSLogix 500

Let’s say we have a rotating beacon that is mounted near a conveyor. For safety purposes, the beacon turns on when the conveyor is running to let the plant personnel know that the conveyor is operating.

Everyone agrees it would be better if  the beacon came on for 5 seconds before the conveyor starts.

The conveyor is automatically started from another section of the plant.

We want the beacon to turn on as soon as the run command is given.

However, we need to delay the start of the conveyor for 5 seconds after the run command has been given. That way, the beacon will be on for 5 seconds before the conveyor starts.

We will do that with a TON (Timer On Delay) instruction. Watch the video to see how.

Addressing in RSLogix 5000

Before you can program any PLC system, you have to understand how the addressing is done in that particulaur PLC. I have included a actual screenshot from RSLogix 5000 below that shows examples of addressing in RSLogix 5000.

Read on to get the details. Read more

Connecting to an Allen-Bradley SLC and Going Online

I get a lot of questions about going online with a PLC. Here is a section from PLC Programming with RSLogix 500 that covers going online with an SLC 5/03.

---

You have written your program and now you are ready to download, or send, the Batching program to the computer. Read more

Setting up an SCP in RSLogix 500

An SCP (Scale with Parameters) is really handy instruction in RSLogix 500. It scales any range of values to a range defined by the programmer.

One of the common uses of the SCP instruction is to take the value from an analog input and scale it to an engineering value. Read more

Troubleshooting A PLC With RSLogix 5000

Excerpted from How To Troubleshoot With A PLC

Let’s consider a batching system just like the one we worked on earlier, except that the PLC is an Allen-Bradley ControlLogix. The software we use to program a ControlLogix PLC is Rockwell’s RSLogix 5000.

TROUBLESHOOTING OPERATION #3

BATCHING SYSTEM WON’T PUMP FINISHED PRODUCT Read more

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