Siemens Step 7 Count Number of Bits Store Result as Integer

I am using Siemens Step 7 with an S7-400 Procesor. I am looking for a sleek way to count a number of bits and store the result as an integer.

My specific application requires me to know the number of valves open without error. Each valve open without error will provide a bit indicating such. I would like to take all the bits (9 in this case) and determine if 2 or more are open.

I can do this in 45 wrungs by placing all the combinations in pairs in series, but surely there must be a better way.

Any Ideas?

Hi!

Can the bits update a simple up counter?

Regards

So all nine in parallel with each one having its own positive edge bit to trigger and up count, and something similar for down count. That may work,

I would put a elapsed time between each input and the set of the counter.

You can have a situation where the PLC when takes the picture of the inputs, it will set several bits, and all of them will result in only one position up in the counter.

If you delay between them, you will be certain that each input will be scan individually and influence individually the counter.

Regards

If they are in 1 word, i/e/dbx.dbwy then

L dbx.dbw1y
T #tmpholder

L 0
T #Count

L 9
CNT: T #LoopNumber

L #tmpholder
SRW 1
T #tmpholder
JZ over

L #Count
+1
T #Count

over: L #LoopNumber
LOOP CNT

Or use FC99 BITSUM from StandardLibrary / TI-S7 ConvertingBlocks.