HI_BYTE AT %MB0: BYTE;
LO_BYTE AT %MB1: BYTE;
No code required.
[/quote]
You should note that if you use global store in this way, you can get trouble in acyclic programs; the M-contents are overwritten from the interrupt-call. It is so with Simatic, probalby also with CoDeSys.
With a grain of salt
Kalle