A simple question about plc/hmi


Thread Starter


My name is Tom, and I have several questions.

I will use a log splitter for this example.
Can I install a plc with hmi on a splitter to perform the following functions?

1 If I have an electronic indicating pressure transmitter switch installed in the pressure port on the splitter, can i install a plc to turn the splitter off if I happen to reach a pre-programmed pressure and sound an alarm? Like I didn't want the hyd. system to over pressure.

2 If the ram makes a run and there is no log to be split, thus giving a low pressure reading, can you program a plc to sound an alarm?

3 Do I need a hmi to turn system on and off or adjust pressure settings?

And does anyone live near stockton, Ca. that would like to help a guy out?

I don't have $, but would be willing to barter my work, or If I showed you my idea and you saw hope, I would pay you upon sale of invention.

Its not a splitter.

Thanks I have been looking forever for help on this matter.
This is a well established technique in press applications. In simple applications people typically use a pressure switch. If the setting is not critical, then a simple mechanical switch with a contact output can work well enough. There are switches with electronic settings and built in displays and keypads if you need a more precise setting. Taking the reading into the PLC and displaying it on an HMI panel can also be done if this provides a better user interface.

So, the answer to your question is that this can be done, and in fact is very common. As for over pressure, you will need to look at the response time. If you are trying to avoid damaging the product you will have to see if the system (including the valves) can react fast enough. If it is for safety reason, then you are approaching the problem the wrong way.

As for helping you, I have no idea where Stockton is. However, if you find out who distributes PLCs in your area they should be able to put you in touch with someone who can do this for you. As I said, the technique is well known in press fit assembly applications and there is lots of hardware meant for the application.
Tom in Stockton, CA,

Take at look at the Zelio - a very cost effective piece of kit for your application. Easy to program in FBD.

I'm using one to control a number of hydraulic rams in a pressing/molding application.

Tom in Mayo, Ireland