That's odd most of these PLC are programmable with IEC 61131-3 languages,e.g. Structured Text which has For-loops. That said i did my fair share of metaprogramming as these usually lack dynamic allocation.
Most PLCs these days support 1131! My whole career in industrial automation was on older PLCs that were produced before 1131 existed. (And long before they added the "6"!) Lots of them are still running factories today. Not one of them supported anything like a for loop. The only loop is the whole program scan loop.
