floating point to two int

jimcav · Feb 15, 2005

Hello Everyone

I am using a ab 1500 and i want to take a floating point value ie F8:0
and turn it into two int., n7:0 to the left of decimal and n7:1 to right of decimal. example if i have 16.0025 i want n7:0 to = 16 and
n7:1 = to equal 0025. i see a problem with n7:1.

thanks
jim cav

USDutchman · Feb 15, 2005

Move F8:0 in N7:0.
Subtract N7:0 from F8:0 and multiply by 1000, which can be done with one compute (CPT) statement. AB PLCs (in contrast to many others) will do all the conversion between datatypes for you

bernie_carlton · Feb 15, 2005

My only concern would be - in the MOV from a float to an integer does AB round or truncate the decimal?

panic mode · Feb 15, 2005

as far as i remember it rounds...
so if you have 16.058, result would be 16 and 58
but if ou have 16.888 result would be 17 and -112 for example.

(edit)

this means you need two instructions:

CPT N7:0  F8:0 - 0.5



and



CPT N7:1  ( F8:0 - N7:0 ) * 1000

Mark Buskell · Feb 15, 2005

Try it this way

BST MOV F8:15 N7:40 NXB SUB F8:15 N7:40 F8:16 NXB GRT F8:16 0.0 MOV N7:40 N7:41 NXB LES F8:16 0.0 SUB N7:40 1 N7:41 NXB LES F8:16 0.0 SUB F8:15 N7:41 F8:16 NXB MUL F8:16 10000.0 N7:42 BND

This way the decimal value is placed in N7:42 and
the whole portion is in N7:41

For example:
16.1234 would place 1234 in N7:42
16.123 would place 1230 in N7:42
16.12 would place 1200 in N7:42
16.1 would place 1000 in N7:42

My example just looks at the first 4 decimal places.

panic mode · Feb 15, 2005

4 places?

BST CPT N7:0 F8:0 - 0.5 NXB CPT N7:1 ( F8:0 - N7:0 ) * 10000 BND

Mark Buskell · Feb 16, 2005

Very Nice

Panic Mode,
I like your solution a lot better than mine for the 50* processors but I don't think the 1500 has a compute function.

ChuckM · Feb 16, 2005

Mark, I think the 1500 can do it with a CPW instruction. I'm not sure on this though because I normally only use 5/01 and 5/03 processors.

floating point to two int

jimcav

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USDutchman

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bernie_carlton

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panic mode

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Mark Buskell

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panic mode

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Mark Buskell

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ChuckM

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