Bit order in a double from S5 to winCC

I am in need of a little help here.

I am in the process of doing some major modifications to a WinCC and step5 program, unfortunately I am not in possesion of a PLC to test out the changes I am making, until I have a chance to load it onto one of our cranes.

I am 'bit' picking from some tags, but I am not sure of the bit 'layout'.

The tags concerned are all doubles (EG ID0, QD0, MD0). Lets take ID0 in this example, I know that ID0 contains IB0, IB1, IB2 and IB3. In WinCC, I select tag 'ID0' (or whatever that tag is called), then select the bit, this is where I need help. The tag selection layout in WinCC is:-

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16

 

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

So are:-
bits 0 to 7 from IB1
bits 8 to 15 from IB0
bits 16 to 23 from IB3
bits 24 to 31 from IB2

That is the way think I they should be, but I am not sure. I would like to get this right first time, because if I am wrong there are a hell of a lot of changes to be made during commisioning.

Paul

Hi Paul


bits 0 to 7 from IB3
bits 8 to 15 from IB2
bits 16 to 23 from IB1
bits 24 to 31 from IB0

Kev

Thanks Kev,

I have just taken a look at my handwritten notes and your answer is the same as what I had actually written down.
So what I had posted was not even what I thought it was.

Still you have saved me from what could have been an extra load of work.

Paul