C-More Micro HMI Read Function Keys from AutomationDirect

The PLC doesn’t actually read the function Keys … Instead, since the C-More Micro writes the key status to a TAG down on the PLC. Then the PLC can read that TAG and take the appropriate action. Each key is mapped to a bit in one of these two words here. So for example, if I hold down the F5 key, we can see that bit 4 at this 100 address – watch this guy right here while I hold down F5 – so bit 4, which is decimal 16 corresponds to function key F5. And F1 for example is bit one at that TAG. Let’s see how to set that up. You can reach that from the Navigation window’s function tab – PLC to panel - or under the Setup Menu – PLC to Panel. Under the Panel to PLC tab – we just enter the PLC TAG where we want the Panel to send the current SCREEN NUMBER – not the function keys – the screen number. We’re using the SCREEN NUMBER TAG which is at address DS100 on a Click PLC. Then the C-More Micro will use the next two addresses – 100 plus 1 an d100 plus two in this example - to automatically store the function key status – IF we enable it by checking this check box. Each bit in these two words shows the status of a single key – an arrow key, a function key, a numeric digit on the bezel, etc. The mapping of those keys is shown in this little chart right here. So “F1” will be bit 1 in the address plus 1. The decimal key will be this 15th bit in address plus 2. Let’s try that and see how it works. Bring up the simulator and save the project. So now anytime a key is pressed, we should see that result in these two words. So lets see, F1 was that first bit at the offset of 1, and there it is … I’m looking at this TAG right here. And when I let go, that status goes away. Let’s see, we said the decimal point was the 15th bit of that second word. And sure enough we can see that in this TAG over here. So each key is mapped to a single bit in one of these two words. There’s a whole video showing you how to read screen numbers from a PLC so check that out if you want to learn more about that. That’s all there is to reading Function Key Status – be sure to check out the other videos in this series. And as always, please send us any topics you would like to see covered – or - any other comments for that matter – we appreciate the feedback!