first scan on bit

hi,
i need a first scan on bit like in s7200 plcs, but in s7300 plcs there's no such bit.

when i use ob100 and write

an m0.0
= m0.0

m0.0 allways remain 1

so i decided to use ob1_scan_1 and wrote this:

L #OB1_SCAN_1
T MW 0
NOP 0

A M 0.0
AN M 0.1
= M 0.2
so my first scan bit is m0.2

is there an easier way for this?

Hello tny;

Try this, it works for me:
Set M0.0 in OB100;
Reset M0.0 in OB1.

Hope this helps,
Daniel Chartier

dchartier said:

Hello tny;

Try this, it works for me:
Set M0.0 in OB100;
Reset M0.0 in OB1.

Hope this helps,
Daniel Chartier

Click to expand...

Don't forget to do the reset at the end of OB1, otherwise any tests you make after clearing it will get a false result!