Hello,

additionally also what exactly USB adapter you want to connect. I recommend be careful to not do that, better look at specification of exactly expected comm port of S7 CPU. You can easy damage something at your side in case of some pin can have 24V and you have poor adapter without any protection. This is also maybe recommendation why not.

Hello,

Gustavo Banchetti

If for S7-300 you mean the CPU the answer is no. The CPU are equipped with MPI or DP profibus by default set to 187,5 kb/s the MPI and 1M5 b/s the Profibus. Two baud rates that the commons RS485 converters don't reachs.

yes fully agree, therefore I've asked what exactly adapter is expected to use. On other side, your infromation can be bypassed without problems because also speed 9600 and higher to max supported to generic converters can be set to MPI and PB DP also. Attention must be taken to mentioned possible 24V on pin as Voltage supply so HW can be easy damaged, as I mentioned. As next recommendation, in case of Gateways (as many of this Siemens adapters are) use internal definition of data exchange as Siemens driver defines and therefore hard to work in case that signals from generic serial port aren't converted correctly. All depends exactly to what Siemens adapter is expected to be replaced with generic type. as example what can be replaced is typical old S7-200 PPI adapter, not Multimaster cable. This is typical generic RS232 to RS485 adapter so no problem use any generic type of adapters with same signals.

Hello,

sry also for offtopic, my English is also not good. Really, I have many times so much work to do to write some serious descriptions about technical terms Generally recomemndation is check every time that pins about Voltage. I know that special adapters have own protection as mandatory. Other things are typical serial ports.