[Scheme]: about S5 cable

Luca_Brasi · Post by **Luca_Brasi** » Sat Sep 12, 2009 7:09 am

hello
Make a decision to made this cable for

http://img33.spamm.us/img33/4072/comtty0.gif

I`m worry about GND connection between PC and PLC
no galvanic isolation or I`m wrong?
Whether this make a any trouble or damage the PLC?
Best regards

zxcslo · Post by **zxcslo** » Sat Sep 12, 2009 6:32 pm

That's why you must NEVER connect cable, when your PC is on.
You will damage COM port. Been there, done that...

That's known fact by PC connection over COM port to S5 PLC.

There is no problem, when you have original PG (programming device) from Siemens, because PG have this chip inside...

Regards...

Luca_Brasi · Post by **Luca_Brasi** » Mon Sep 14, 2009 8:14 am

If i use laptop (powered by battery)i don`t have a problem?

zxcslo · Post by **zxcslo** » Mon Sep 14, 2009 11:28 am

Theoreticly maybe yes, but I wouldn't be so sure.
Specialy on laptops, where you can't replace the com port, when it's damaged.

regards...

Coyote · Post by **Coyote** » Tue Sep 15, 2009 7:07 am

I have already programmed S5 with such cable without any problems with laptop. Only now I see that port could be destroyed, I didnt pay any attention for that.
When building this adapter I was thinking of adding a DC/DC converter like TracoPower TMV0505EN http://www.psui.com/pdf/tmv-en.pdf but I couldnt find nothing similar in a local store. This might be a good upgrade for this adapter.

zxcslo · Post by **zxcslo** » Tue Sep 15, 2009 2:36 pm

Why don't you look at this:

http://www.traeger.de/simatic-s5-interf ... b-tty.html

I have used this S5 cable (I still have one) and also MPI/PPI cable from them.

Regards...