ABB Prokontik - DIN 19239 style programming language

Dear Engineers,

I think you can help me with understanding old style PLC code from ABB Prokontik. (DIN 19239)

Please see attached photo from code hardcopy.

I need to understand how the serial communication works and what are those (looks like German words) commands about?

I am completely guessing, but this looks like a device declaration to me. Teilplan is partial or subplan. Gerate is equipment (per translator). Are there more pages to your printout?

Google corrected the spelling to Procontic and I was able to find this manual:
https://library.e.abb.com/public/72a20a5228b48ff7c1257c2100539c1a/2CDC120108M0201.pdf

Take a look at that.

This looks like instruction list, using two valve (=ventil) function blocks. The line going to the left (input) or right (output) indicates direction of the signals.
M 305 would be internal flag 305.
T6 would be the assigned timer for watchdog timeout and its preset # 150.