Help!) Command error MSG in S7

Hello! Guys! I finally solved the problem of convert S5 to S7 !
Really thank you for your advice!

And then, I have a question about command in Funtion Block .
'DO' (in S5) -> 'TAK' (in S7)


1. Why does this PGM act number 1 (SLW 13 & SRW 13)

2. Why does this use the same command in a different way(SLW3, SLW4)??

Thank you for your help

1. It guarantees only the least significant 3 bits of the word will remain.
2. Using SLW 4 for DBs is because in S5, the DB values were words, but in S7 they are bytes (1 word = 2 bytes).

TAK in S5 swaps the two accumulators i.e. L DW10 L DW12 TAK swaps the two round DO processes the word for example L KF 10 T FW100 DO FW 100 L DW 0 will actually load DW 10 as pointed to in ACC 1 so the DO instruction loads the word pointed to in FW 100.

Further to the information given by @sigmadelta

S7 pointers use the bottom 3 bits as the bit number while the upper bits are the byte number.

In the code, The bit number is in MB212 and the byte number is coming from MB213.


The instructions above strip out any extraneous bits and leave only the bottom 3 bits in ACCU1


The instructions above get the byte number, shift left 3 and or with the bit number in the format xxxxxxxxxxxxx.yyy where X is byte number and Y is bit number.

Nick