Siemens AS511


Thread Starter

David Myers

I have a Siemens 101U from the stone age with the RS232/TTY converter cable. I also have the Step 5 programming software, but it only supports AS511. What is AS511? Can it be used with the above-mentioned cable and PLC because I can't get them to shake hands??
AS511 is actualy just a serial port. what most people run into id that step 5 does not work too well in windows envirements, boot to dos and set it up for comm 2.

Piotr Kowalski

During the days of the stone age people used to conect S5 PLCs to their PC's
by means of RS232/TTY coverter. :)))))
If you do that and choose the AS511 intreface in your Step5 software shall
be OK, assuming you got proper operating system and Step5 version.

Good luck!

Donald Pittendrigh

HI All
David, how can you insult me by placing me in the stone age, this is still a
new PLC comparatively speaking, I go one series further back with Siemens to
the 150A PLC, ten years earlier!!

To answer your question, in the dark ages, before the stone age, there were
two serial interface cards and two serial protocols used at Siemens, the one
was a 6ES5 512 ?AA10 and it did AS512 protocol with RK512 procedure to
couple PLC's together, there were also a few other procedures available, but
that’s off topic, the AS512 name came from the card serial number and the AS
from the German word Anschaltung, or interface. The serial number of the
other card was 6ES5 511 ?AA?? and it used AS511 protocol to communicate to
programmers. Later on a procedure was developed for AS511 to use it for
comms to other serial devices.

So to answer your question, the gear you have, should fit together, you
should be able to test your S5 programming package and converter on any S5
PLC and you should be able to communicate to the 101U with any S5 programmer
that works elsewhere, so that is how I would go about determining where the
problem lies, however having found the problem, you may have some difficulty
getting the 101U repaired and you are unlikely to ever derive much pleasure
from the 101U, so I suggest you "can it" and fork out a few bucks for a new
S7200, it will probably be cheaper in the long run.

Donald Pittendrigh

Michael Griffin

AS511 is the serial communications protocol programming devices use with S5
PLCs. This is what you would normally pick to use the cable you mentioned.

I have only seen pictures of the S5-101U, so I don't know if there is anything
different about it. Does the Step-5 software recognise what a 101 is at all?
I would be simply guessing, but perhaps Step-5 doesn't support the S5-101U
and you need to use a hand-held to program it.

Michael Griffin
London, Ont. Canada

Daniel Chartier

Hello David;
Stone age indeed!
The S5-101U is a very old beast, programmed under PCPM through a dedicated programmer PG635. You cannot use Step 5 on a PC with the TTY/RS232 converter cable in order to program a S5-101U. Sorry.

Hope this helps,
Daniel Chartier

Andrew Hawdon


The standard interface on all S5 PLC's is AS511 and requires an RS232/TTY converter. You have all you require. Have you used S5 before on the PC you are using? What version of step 5 are you using? What is your OS? All of these can have an impact on communication. I have used a standard RS232/TTY cable to communicate to a 101U before, so it does work.

> What is AS511?

AS511 is the protocol used for Communication between pc and S5-PLC.

> Can it be used with the above-mentioned cable and PLC because I can't get them to shake hands??

I'm using this combination since many years, and it works fine. Is your cable wired correctly to match the specs of the S5-101U-connector? (aktive/passive tty)

Andrew Hawdon


Most of what you have been told is correct. However Daniel is not correct, you can program a 101U via the RS232/TTY converter. The PCPM OS was a Siemens OS before DOS. You will find that in the 101U there is a limited number of blocks timers etc and you are not able to download unless the PLC is in stop.

Hi Daniel,

in 1986 we were using PG675 to program good old 101U.
PG635 was not a 101U dedicated programmer, it came some years after PG675 and was probably the first PG with LCD screen and 3,5" floppy drive.

The 101U could be programmed with PG670, PG675 and handheld programmer PG605. The PLC's AS511 port provided the 20mA supply for both TX and RX loops, so the use of passive RS232/TTY converter should be possible (handheld PG605 was powered by the PLC AS511 port).

Despite the stone age, good old 101U could be connected as slave in a L1 network (the ancestor of Profibus). Performances? Just one block (PB1 or FB1) and an amazing speed of 1024 logic instructions processed in 70ms.

best regards
Luca Gallina