PLC with 64bit floating point and integer arithmetic?

danw said:

I'm curious where anyone has found a statement that S7-1500 supports 64 bit floating point arithmetic.

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In TIA, I can create LREAL and LINT tags easily.
And any math instuction can handle all kinds of data types, including LREAL and LINT.

AustralIan said:

Danw: from what I can find, they have a type LREAL and LINT, and a separate library of "long functions", eg LREAL_ABS. Most regular instructions don't accept them.

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Where do you find this library with "LREAL_ABS" ? It sounds as it returns the absolute value of an LREAL. There is an "ABS" instruction that works with any data type. No need for a special library.

JesperMP said:

Where do you find this library with "LREAL_ABS" ?

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When I open Portal it is the 4th built in global library I see:

• Buttons and Switches
• Drive Lib 1200 1500
• Drive Lib 300 400
• Long Functions

I agree, the standard math instructions all seem to take Longs, at least in V14. My assumption is that there was a time where the extra library was needed (V11 for the 1200? V12?), and they eventually expanded the standard functions without deleting the library.

LREALs and LINTs work with the standard instruction set in V13 SP1 as well (which I still use).

Didn't they put man on the moon within a few hundred yards of target with 8-bit microprocessors ?

Surely there's another way to make these "precision" errors less demonstrative....

There's a couple of people on here who I am sure have the skills to suggest something, but I don't like to name names...

Be careful with your anecdotes. Here in the US "they" used to travel from Missouri to California by horse and wagon. And every once in a while "they" had to eat each other along the way.

Just because something was done a certain way in the past, often successfully, doesn't mean there isn't a better way to do it today. If you aren't tied to a platform and long datatypes are that important to you, use a platform that supports long datatype arithmetic. There are enough of them available.

Keith

kamenges said:

Be careful with your anecdotes. Here in the US "they" used to travel from Missouri to California by horse and wagon. And every once in a while "they" had to eat each other along the way.

Keith

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But.. "Mission accomplished"

kamenges said:

If you aren't tied to a platform and long datatypes are that important to you, use a platform that supports long datatype arithmetic. There are enough of them available.

Keith

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Assuming that "long datatypes" will be good enough.... I was just saying that there are more ways of killing a cat....