Silly question: bits calculation MOV command

[captainpatje 0]

Dear all,

Just to let you know: I am not an PLC expert, but for my job I was send to our headquarters in Taiwan to learn basic PLC programming.

For context: We sell bandsawing machines (metalcutting saws) for industrial use, and we sell certain options with this (blade deviation detection, mist spray, laser light) which all use inputs/outputs on our Mitsubishi FX3G plcs.

Now I must say that I have learned more than originally thought, but one important thing I am not familiar with, which is the calculation behind bits.

What I mean by this is, when you use the MOV command, f.e K4X020 K4M020, I know this means K4 actually means 4x4=16bits it moves.

But then I don't know where the gap is, because I am tempted to count like this:

x20 = m20
x21 = M21
x22 = M22
X23=M23
x24= M24
x25=M25
x26=M26
x27=M27
x28=M28
x29=M29
x30=M30

etc

But i know this ain't right, because I should count until x25 and then forget x26, x27 and then go further with x28. Or something like this!

This is the easiest way how I could explain the problem I am facing, again I have not really mastered the knowledge of bits, but could someone explain to me how I should know which inputs/outputs I should skip? I was told once but I completely forgot.

Thanks in advance!!

 

Edited 14 Nov 2019 by captainpatje

[Inntele 60]

X28 and X29 with FX3G

LOL

"This is the easiest way how I could explain the problem" you're facing.

Edited 14 Nov 2019 by Inntele

[Gambit 324]

Hey Dutchie,

Je hebt het waarschijnlijk over een FX en die telt octaal 0-7 . Dus 8 9 en 10 bestaan niet.

 

 

[captainpatje 0]

24 minutes ago, Gambit said:

Hey Dutchie,

Je hebt het waarschijnlijk over een FX en die telt octaal 0-7 . Dus 8 9 en 10 bestaan niet.

 

 

Ha! Ja dat klopt. Oh dus het steekt zo in elkaar. Bedankt! Duidelijk!

PS. Zit ik verdomme in mijn Device list te kijken zie ik inderdaad dat 8 en 9 niet bestaan. Zoveel kennis heb ik er dus van Weer wat geleerd!!

 

In English: @inntele, dang, I looked in my device list in GX works and can indeed see that 8 and 9 are non existent. Shows you how much knowledge I have of this haha!

Well hey, I am glad that you guys could understand my nonsense explanation and made some sense of it! Thanks!

Edited 14 Nov 2019 by captainpatje

[Inntele 60]

There is an instruction (D)PRUN [FNC 81], which copyring an octal set of bits to an octal set of bits. For example, PRUN K3X16 K3M16 will copy:
X16 -> M16
X17 -> M17
X20 -> M20
X21 -> M21
X22 -> M22
X23 -> M23
X24 -> M24
X25 -> M25
X26 -> M26
X27 -> M27
X30 -> M30
X31 -> M31

https://dl.mitsubishielectric.com/dl/fa/document/manual/plc_fx/jy997d16601/jy997d16601q.pdf  , page 460

 

Edited 14 Nov 2019 by Inntele