Mask out 16 bits in a word

Berra

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• May 5, 2010

• #1

hi experts.
I have a small thought: how can I mask out a 16-bit words.

each bit of the word is to a picking station. So if the bits are set as this: 0100 0100 1000 0100
and I'll bulge out the boxes to the picking stations first station 3 then station 8,then station 11,and then station 15

or can I compare the word instead of hexcode
brainstorm example:

l / 16 # 8908 barcodes reader
l / 16 # 8908 mask
== I
Set M1 / bulge out box to the picking stations

 

TConnolly

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• May 5, 2010

• #2

I'm not sure I fully understand what you are asking...

Define
Station1 = 1
Station2 = 2
Station3 = 4
Station4 = 8
Station5 = 16
Station6 = 32
Station7 = 64
.
.
.
Station15 = 16384


Bitwise AND the reference word with the defined station numbers. If the result is non-zero then the station bit is set.

You can add the stations together to build a more complex mask:
Mask = Station2 + Station8 +Station11

 

Berra

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• May 5, 2010

• #3

yes you have under stand it
station 1 = 1
.
.
.
but how do a bitwise the word?

 

jkerekes

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• May 5, 2010

• #4

What PLC brand?

 

Berra

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• May 5, 2010

• #5

sorry Siemens step 7

 

Brodin

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• May 5, 2010

• #6

It sounds like an AND WORD (AW) operation should work for what you are trying to accomplish.

 

Berra

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• May 6, 2010

• #7

Ok i will givit a try

 

Lare

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• May 6, 2010

• #8

If I understand this right, you can use bit addresses directly to this on Siemens, you don't need and inscructions for this.

I mean, ex. word address MW0 uses bit addresses M0.7-M0.0 and M1.7-M1.0.
If you have value 3 on MW0 then, if you look at bit addresses you see that bits M1.1 and M1.0 are on. If you have value 8 then only bit M1.3 is true...

 

Last edited: May 6, 2010

shooter

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• May 6, 2010

• #9

lare is correct only counting is difficult.
better is stationword AND workword if true the set.
or
do it with ror or shift. and a counter.

 

Brodin

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• May 7, 2010

• #10

Lare said:

If I understand this right, you can use bit addresses directly to this on Siemens, you don't need and inscructions for this.

I mean, ex. word address MW0 uses bit addresses M0.7-M0.0 and M1.7-M1.0.
If you have value 3 on MW0 then, if you look at bit addresses you see that bits M1.1 and M1.0 are on. If you have value 8 then only bit M1.3 is true...

Click to expand...

True, but with the AND WORD function, he can look for several stations at the same time as well as ignore any stations with a single function (less code to write).