RSLOGIX 500

[Brad 0]

I am using a CPW comand to move a word to another file were I need to multiply the word, (or would like to) instead of each bit in the word. can this be done?

[TechJunki 0]

You can multiply a word by using the MUL function.

[TimWilborne 108]

Do you mean multipy each bit in a word or multilpy each word that you are copying by something(example need to multiply N7:0 through N7:5 by 5)

[Brad 0]

TWControls, Yes that is what I am trying to do. If I just use the MUL it only multiplys one bit!

[TimWilborne 108]

Which one. If what you stated is what you are trying to do, use techjunki's post. If what I stated is what you want to do, how many are you trying to manipulate and do you need to do it in a single scan. The easiest solution depends on these things.

[Brad 0]

TWControls, I am trying to do what you wrote. I have copyed a word N15:0 through N15:6 and move it to N80:0 through N80:6 I need to multiply in one scan.

[TechJunki 0]

I think you may be a little confused between a word and a bit: A bit is addressed as N80:0/1 -- one bit (bit 1) of a 16 bit Word The word would be N80:0 -- One 16 bit word A group of seven words is what you are working with N80:0 to N80:6. Are you trying to multiply all seven word together or multiply all words by a certain number?? Explain the math you want to perform?? I assume you are using a Micrologix PLC what version is it, as the instructions vary among the different series. Edited 16 Dec 2005 by TechJunki

[Brad 0]

You are right I am confused sorry. I am trying to multiply, N80:0 through N80:6 by 2 at one time. using a Micrologix 1500 Edited 16 Dec 2005 by Brad

[TechJunki 0]

Just to clarify this is the math N80:0 x 2 = N80:0 N80:1 x 2 = N80:1 N80:2 x 2 = N80:2 N80:3 x 2 = N80:3 N80:4 x 2 = N80:4 N80:5 x 2 = N80:5 N80:6 x 2 = N80:6 And you would like to do this with only one instruction??

[TimWilborne 108]

For just 7 values I would use the MUL 7 times like Techjunki said. If you have a boat load of them to do might be able to do something similiar to RsLogix 5000s FOR statement but it's a real pain in RsLogix 500.

[Spedley 0]

I don't think such an instruction exists. Your only real option (there are other more complex ones) is to have a seperate multiply for each word.

[Brad 0]

Yes.

[TechJunki 0]

I think the simplest way to do this would just be to branch 7 MUL in one rung and multiply them all individually. There are other ways but they are unecessarily complicated for this.

[Brad 0]

Easy is better. Thank-you all for your time and the help!

[TConnolly 13]

Unfortunately, FAL (which can do math operations on multiple words in a single instruction and scan) is not available on the ML1500. TechJunk has suggested the best option for for the ML1500.

[hakko808 0]

Would a rotate instruction be helpfull here? Since multiplication by two just shifts one space left? Usually bit shifts are quicker than multiplies.