JaySharp90

PLC Memory & Pop-ups

6 posts in this topic

Hi all,

Three quick questions:

I have been referring to a past post about the PLC memory areas  (http://forums.mrplc.com/index.php?/topic/31572-omron-plc-memory-areas/) that seems to suggest W memory is cleared after a restart but that maybe D memory persists. So if I have a complete shutdown of all power, will whatever I store in D remain the next time I start up?

Also related to memory, in terms of global vs local symbols: if I store a value in some local symbol  i.e. w100 in Program 1, can it be used in a separate program (i.e. w100 in Program 2 is same as W100 in Program 2) or does that require the symbol to be a global symbol?

I'm trying to find out how to trigger a pop-up error message on the HMI screen from the PLC, but I'm a bit lost as to where to start. I'm using a CJ1M-CPU, with an NS series HMI. In (http://forums.mrplc.com/index.php?/topic/20366-nq-designer-popup-an-alarm/) IO_Rack mentions something about writing values to System Word Memory, but I can't seem to find any information about this. If someone could point me to the correct manual or give me some tips that would be great. I also found something about using Machine Navigator (in V088-E1-03) that sort of looks relevant, but I'm not entirely sure.

Thanks,

Jay

Edited by JaySharp90

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Both D and H areas are memory retentive - W and CIO are not. Battery needs to be in place though. Global symbol required - that is all I use. Have not had to do pop ups.

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Thanks Bob, that's good to know. I've found myself using a lot of global symbols as well but wasn't sure about conventions and the like.

Thanks Jay, I had no idea about the sheets and frames, but this isn't exactly what I had in mind (sorry, I might not have been clear). I have been using the pop-up screens within the HMI fine currently and triggering them with command buttons, but what I was wondering was if I could trigger them via the plc - so some command in cx-programmer. The idea is to run a check of something, say water level in a tank, and if it is too high that sends a signal to the hmi to pop-up a message to the user. Currently I'm just using a red led :/. I'm not fixed on using pop-ups if you can suggest any other way to perform the same function.

Cheers

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Make the Pop Up screen as per Jay's document.

The Pop Up screen can be triggered from the PLC using the $SW Allocation Address. After assigning a PLC address for this area in the NS, populate the (Assigned Address +1) with the screen number of your pop up.

MrPLC_PopUp.jpg.00927dc41148c9ccf542b3a5

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