Help with HMIs (PanelView Plus Compact 400)

[Evilbeard 0]

Hi. I'm taking a class through my job (I'm an industrial maintenance technician), and they've offered us the schooling through our local community college. They bring the trainers and laptops to our site, and we have class there. We're in our "PLC II" class, and we're using CompactLogix 5332E 1769-L32E PLCs with PanelView Plus Compact 400 HMIs. I'm having issues with getting my PLC to work properly with the HMI. I have a very simple program. A pushbutton turns on a timer with blinks a light. I have my tags as Green_On and Output_Green. They're obviously aliases for Local:1:Data.0 and Local.2:O.Data.0. I created a screen in FactoryTalk View ME, and gave it two simple pushbuttons. One a Maintained and one a Momentary. I created tags in the HMI, and linked them to the tags in the PLC. I have the button properties set as such: I create the runtime application and send it to the HMI. When I push the buttons on the HMI, I get no response from the PLC. If I push the manual pushbutton on the trainer, the PLC reacts appropriately and the buttons on the HMI change state (from the tag indicator). What am I doing wrong? Obviously the HMI is seeing the PLC, because the pushbuttons are updating the to tags change in state from 0 to 1. Why is it when I press the buttons, I'm not writing the value to the tags and the PLC changing state? I've talked to the instructor, but he's been retired for some time, and while he's given us a good overview of the basics, he's a bit out of his depth. Edited 24 Sep 2015 by Evilbeard

[Giarc 0]

First thing I'd recommend is rather then trying to read / write directly to the inputs / outputs is to create some Boolean tags and use those in the HMI addresses instead. Then program those bits in the PLC to do what you want. Input addresses will be overwritten with the physical module input value. (Example: if it's the local input address for a 24VDC input. The actual state of that input is what the value will be regardless of what you send it from the HMI)

[hboyer90 3]

Don't make your input tag an alias, just make it a base tag. Next, in your plc program make a rung for the light output and for the inputs put the physical button Local:1:I.Data.0 in parallel with the input tag. This way either the physical button or the hmi button will turn on the light. If you alias the input tag to the physical push button, you will never be able to control the output with the hmi, the hmi button will merely be an indicator of the state of the push button. An hmi button will never be able to control a physical switch, right? So that's why the hmi button needs to just be a Boolean tag, a bit that turns on and off, separate from the switch.

[hboyer90 3]

Here's how to do it: Link to the image for higher resolution: http://i.imgur.com/EdY1bXQ.jpg The light can be controlled by either the physical push button, or by your hmi button (GREEN_ON). GREEN_ON will be turned on and off from the hmi. Make sense? Feel free to ask any more questions. Howard Edited 25 Sep 2015 by hboyer90

[Evilbeard 0]

Yeah, it totally makes sense now. I changed my program, and everything works great. Thanks for the help, guys.

[hboyer90 3]

Good to hear. Good luck in class!