Extract part of an integer in MicroLogix 1100

Hi All,

I am communicating with a cognex camera from a MicroLogix over EIP.

I am reading in a part count and a Pass/fail (1 or 2).

My issue is that the two integers are being written into the same int file (N15:1). When I view them as HEX I am seeing 3802 for example. When you separate this it reads 38 02, which in HEX means 56 2 which is 56 bottles and a fail, which is correct and accurate every time.

Is there a way to use the EQL command for the first half of the int N15:1?

Maybe something line N15:1.Data[1] or something like that?

Any help is much appreciated, thanks in advance.

Try looking at mask moves MVM, you will move the first have to another N file then you can do a = to

Isolating the bottom half of the word is easy, just AND N15:1 with 255 (or FFh) and put the result in another register. This will clear out the top half of the word and leave you with 02 using your example.

The top half is a bit trickier because you have to shift the bits too. Do an AND on N15:1 with FF00h, this will clear out the bottom half of the word. Then divide the resulting value by 256 and you will have your answer. Dividing by powers of two shifts bits to the right in a word, 256 = 2^8. This method breaks down with signed numbers though so you can't use it if bit 15 is on--which means the value can't be larger than 2^7 or 128.

The BTD instruction is what you want. Take a certain number of bits starting from here and put them in another tag starting there. Make sure you clear the destination word before you execute the BTD, because the BTD won't "turn off" any bits outside of it's effective area that may have inadvertently be turned on, and will give you errors.
Disclaimer: I'm not 100% certain that the BTD is supported in the micrologix processors. I don't work with them much any more! If not, MVM or AND with some bit shifting as the people above have suggested is the way to go.

ASF said:

Disclaimer: I'm not 100% certain that the BTD is supported in the micrologix processors. I don't work with them much any more! If not, MVM or AND with some bit shifting as the people above have suggested is the way to go.

Click to expand...

I don't think the BTD was available in RSLogix 500 at all, no matter what processor.

It should be simple to strip off the data you want in just a few steps
Step 1
Move the lower 2 HEX words by using a MVM function (Masked Move) to a new Integer
This would give you the 02 value for failed count (N15:10)
Step 2
Shift the second 2 HEX words to the right 8 bits using the SBR function (Shift Bit Right) to a new integer. This will give you parts count (N15:11)
This should be all you need to
Play around with the Bit Shift to get it right