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OP 17 Communication Problem !
I cannot communicate from my PC to the OP 17...
By Fred Larsonneur on 27 July, 2003 - 12:23 pm

I tried in many way to communicate.
I use a PC with an USB/ serial converter ( Prolific driver), which is working well with an MPI adapter on S7-300.
The OP is in transfert mode, but when i try to transfert data i have the same thing all the time : E 4027 : Synchronisation faulty.
My COM 1 Port configuration is 19200 Bds,8 bits, parity none, stop bit 1 and flow control none.
I tried in different speed transmission.
When downloading, a brief message appear on the OP 003 Protocol error.
Thanks in advance if anybody had a such experience, to share it.

By Gabriele Corrieri on 28 July, 2003 - 12:06 pm

Hi Fred,

some friends have same problem as you (with different USB/Serial converter) and they have solved using flow control and this more complete com cable


Try and remember to send me your suggestion.

My friend have also tried some time, with different PCs and OSs to use USB/SERIAL adapter with PC or TS adapter for Simatic, with no result, could you send me, also thru my e-mail more references on converter that you've get to do?

Best Regards.

Gabriele Corrieri

Hi together,

I know pretty well, Siemens do not use the com interface as everyone else - that causes some problems with using USB/COM converters (e.g. Prolific!!!).

One solution is the USB PC Adapter from Systeme Helmholz ( with an own USB driver.

Hope that helps,

Best regards,
Konni (

By Anonymous on 28 July, 2003 - 1:58 pm

Hi Fred,

For downloading your OP17 application from PC to OP17 you can connect your PC serially (without MPI adapter) to the OP17.

Good luck