Storing a couple of bytes in a word (AB SLC)

[wnkook]

Hello,

I want to Store two differant values into one integer file.
IE:
1st Value = 50
2nd Value = 120

Integer = -4046

I'm breaking bits 0 thru 6 for value 1 & bits 9 to 15 for value 2

The question is: How to I store and read these two values from 1 integer address.

Just unsure of how to impliment it, do not have a plc to try it out on. Will be doing my debug at the customers during the downtime. But if I can hand check the process it should work there.

Any help would be appreciated

Thanks,

Jason

 

[bernie_carlton]

1. By your assigning 7 bits for each value storage you are saying that they will never be greater than 127. Make ABOSULUTELY SURE that this is correct (especially Value 2) before storing these or you'll have trouble with negatives.

2. Instead of 9 - 15, store the second value in 8 - 14 leaving the top bit of each 8 alone.

3. Storing is easy: MUL, Value 2, 256, Target - ADD Target, Value 1, Target

4. Retrieving is a little harder: MVM, Target, 00FFh, Value 1 - MVM, Target, FF00h, Value 2 - DIV, Value 2, 256, Value 2

 

[wnkook]

Thanks

I starting trying how i could do it in a micrologix here at the shop.

Got it to where it works just about 15 lines of logic and a couple extra words for temp storage.

(was latching bits in another word based off of the bits used in value2 then doing some masked moves like you did)

Yes the value will never go past 120....

This is for Hz on a conveyor system.

I need to change the hz based on differant parts. currently i'm told everyhting is below 60 Hz on all parts.

Thanks again,

Jason

 

[(8{)} ( .)]

Why not use the Swap function. Then you could byte-allign everything. That is unless you HAVE to store data in the particular bits you named...

Use the Swap to put a low byte to the high byte (or vv) the rest can be done with MVM instructions.

Good Luck,

(8{)} ( .)

(Yosi)