NT21 Memory Setup

[IO_Rack 182]

I'm installing an NT21 high function touch screen on a C1000H via Host Link module. The program in the PLC is pretty huge and sucks up a lot of memory. My question is.... Is there anything fundamentally wrong with using LR memory area to control the PT? We have no plans to ever PC Link this PLC. I normally use DM area for PT control but I need to save as much as possible for my data collection. Thanks

[gtsuport 61]

Initially I do not see a problem with using LR for PT control and notify. It can be programmed in NTST v4.7. Unless some of the wiser participants are aware of something not immediately apparent.

[IO_Rack 182]

The only two concerns I thought of off the top of my head were.... LR area is designed to use with PC Link. That doesn't concern me as far as needing it, as stated above. And LR area is not data retentive. That may give me unexpected results at power up. (It wouldn't be unexpected though if I were expecting it.... Right?)

[IO_Rack 182]

MrPLC considers me an Expert now!

[gtsuport 61]

That is true, you will now be expecting it! As you probably know, screen 0 will not exist. You could use a 61.15 (first scan flag) bit to set your initial screen value for your PT control register. I think the other registers will be updated from there. Just a thought. Congrats on becoming an "expert". Someday I will share my definition of an expert.