Data value to Switch on M Flags

[RobinA 0]

Hi I'm sure there is an easier way or simple command to do this rather than the long winded compare i've done. We have a PC linked to PLC, (The PC handles data logging along with other CAD type functions) PC Sets D1000 to 1 : I Want M100 on PC Sets D1000 to 2 : I Want M101 on PC Set D1000 to 3 : I Want M101 and M102 on etc etc The Binary number in D1000 is reflected by Head address M100 + 8 These Flags are set to trigger various other control functions with in System ta

[Veganic 8]

Do you mean: PC Sets D1000 to 1 : I Want M100 on PC Sets D1000 to 2 : I Want M101 on PC Set D1000 to 3 : I Want M100 and M101 on ? If so someone will be along with an answer very soon. If you mean: PC Sets D1000 to 1 : I Want M100 on PC Sets D1000 to 2 : I Want M101 on PC Set D1000 to 3 : I Want M101 and M102 on etc. You may be stuck with compares.

[Gambit 330]

Looks like you need the ENCO DECO instruction. Which CPU are you using ? Edited 2 Nov 2012 by Gambit

[JRoss 84]

If you're trying to get the bit pattern in D1000 to map to M100 and following, then you can just use a move command: MOV D1000 K4M100 The KxMy style of addressing works with a range of bits. The "x" indicates the number of nibbles (4-bit chunks) that you are addressing, and the "y" indicates the first bit you are looking at. So in my example above, K4M100 is looking at M100 - M115. It's mapping the bits in D1000 to those addresses. The "x" can be any number from 1-8, though anything over 4 requires using the double (D) version of the instructions.

[Inntele 60]

For M100-M107 (8points) it has to look like MOV D1000 K2M100. Of course, if the topicstarter want really to get the binary interpretation of D register in M area (as Verganic suggested). Edited 2 Nov 2012 by Inntele

[Veganic 8]

That's the one I was thinking of.. MOV D1000 K4M100. I've not come across ENCO /DECO before - interesting. (Maybe someone should do a "Instruction of the day" thread.)

[JRoss 84]

I use the DECO instruction occasionally to create a simple state machine: DECO D100 M100 K4 In this, D100 is my step number from 0-15. Only the first four bits are being decoded, so numbers above 15 will be decoded according to the first four bits only. M100-M115 are my step bits. I would then use M100 for standby, M101 for step 1, etc. These days I usually just use comparison instructions for step routines. Using the above method creates a smaller (i.e. faster) program, but is harder to understand for the uninitiate. Plus it's platform specific, and I work in enough different platforms that I try to keep things generic.

[RobinA 0]

Thanks guys, that was what I was looking for. ! didnt realise you could just simply : MOV D1000 K2M100