Klöckner Moeller PS21 PRG22 PLC 1979/1983

The German PLC from Klöckner Moeller (now Eaton) PS3 and Sucosoft S30 (v2 1986 DOS) is already vintage. On ebay I found an earlier one. PS24 series (~1979). PS stands for Programmierbare Steuerung (programmable controller) PS24 and PS22 are racks. PS21 (~1983?) and similar PS31 are “small” and thick. First the programmer

Programmed via a PC (DOS, Sucosoft S20), terminal VT 5700 and by different programming devices KSR43, TAS248, PRG 22 (suitcase above, membrane keyboard) or by PRG 311 via lightpen (D-sub DE-9). (The PS3 with PRG 300 also supports lightpen for drawing ladder logic.)

There’s also PRG 24S, a portable computer with CRT and 2x cassette drives (Sucosoft 1 system software loaded via cassette). I like these heavy suitcases. The PRG 22 (membrane keyboard) was especially for the PS21.

PLC and light pen programmer 311 (attached EEPROM is dark gray, the silver dial showing up to 45 minutes battery capacity)

VT5700 (Informatik Museum @mprove photography)

I haven’t found any manuals online, so I bought a book. I still have to read it completely. The CPU is not mentioned. The CPU card for the racks is called EBE 230. One other card has a 6810 RAM. I think the bus is 16 bits wide. An EPROM can store 4096 instructions (words).
Obviously just 5 instructions (OR, AND, NOT, =, jump conditionally, jump unconditionally).
And 5 operands (input, marker, output, timer, NOP). The programming device printing out some tokens/escape codes.
I have to study more and also compare that with the S30 software and manuals. I haven’t found the S20 software. An instruction list looking like this

0000 O  I 0
0001 A  I 1
0002 AN M 4
0003 =  Q 2

I’ve now read my book. Many info can’t be found online, like some more hardware, including simulators. Also some general info about some early DIN standards.
There are no escape codes printed out but this are the keys, one should enter. Menu driven LCD. Copy → Copy all? → Y/N.

The book doesn’t give detailed info about how data is stored internally.
On every of the 4096 memory location there are 16 bits stored.
The operation like O (OR) takes 6 bits, so unclear what is exactly what. The 2 operands in total 10 (LSB).
To show the (user) memory one can push BITMAP. Surprisingly, there are only 10 bits shown.

One can use a regular EEPROM or a programming module, SM2-EPR4 (4 for 4KB). The 2nd half of that has a library of some macros like BCD forward counter.

The full device/PLC memory layout consists of
-User program
-states of input
-empty for libs
-states of output
-user program.

With the programming module, one can transfer some libs and use COMPRESS, where the addresses are automatically adjusted.

There are 2 examples of the macros but they are quite hard to follow. There was an additional book. One can also make own macros.

There’s obviously no COMPRESS function on the later PS3. And the DOS software using some text files and one very small binary with unknown coding.

Cool VT5700 terminal!