Dectect morethan 1 bit set in a byte.

[bernie_carlton]

My pseudocode did, if after removing one bit anything is left then there is two or more. Done.

 

[Paul B]

Not a purist solution, but for a ladder logic guy like me a brute force method would look like this.

Move 0 to integer address with tag name "Bit_Check".

If bit 1 is on, add 1 to Bit_Check
If bit 2 is on, add 1 to Bit_Check
If bit 3 is on, add 1 to Bit_Check
If bit 4 is on, add 1 to Bit_Check
If bit 5 is on, add 1 to Bit_Check
If bit 6 is on, add 1 to Bit_Check
If bit 7 is on, add 1 to Bit_Check
If bit 8 is on, add 1 to Bit_Check

If Bit_Check is greater than 1, more than one bit is set.

In Siemens you could make an FC that would contain the code so it would appear clean when calling the FC in ladder. Just another take on the solution, there are as many ways to do it as there are programmers.

 

[BobB]

Geez - it is easy in Omron - mask the byte to another word, use the BCNT (bit count) function and do a compare.

 

[KalleOlsen]

@BobB
Like S7, presumably ...

 

[BobB]

OOHHH! That is new. Last time I used S7 I think it was Jesper posted some code to manufacture a bit count instruction for me.

 

[TConnolly]

Its easy in almost any respectable PLC.
Here it is in something old, a PLC/5.