convert usb/rs485 for S7200 ?

hello
I wanted to know if someone has a schematic on a convert usb/rs485 for S7 200
my converter rs232 rs485 for s7 200
that works very well (photo below)
but I wanted to make one with a usb connector, you have a schematic ?
thank you

my production rs232/rs485 for S7 200 ---->

http://www.monsterup.com/upload/1240922807506.jpg

http://www.monsterup.com/upload/1240922807564.jpg

you can use USB/Serial converter for this purpose... but make sure the converter should be the one which contains the circuit box in it, not that the simple one.

can u give me the circuit of RS 232 to 485 converter? It will be nice if u could give this circuit

Parag

thank
but you indicates a commercial mounting
which must be purchased (prog C.i.)

I want to make a same assembly me as for the rs232 rs485

Don't waste your time as you will also require a driver for Windows. Go and buy one it will cost you a whole lot less. Dveleoping and testing the driver would cost you perhaps 20-50 times the cost of a commercial one - and then there is no gurantee it will work with your PLC. Even commercial ones do not work a lot of the time.
I have just used an Adam 4561 from Advantek. It was seamless from a computer running Vista and Omron PLCs from Omron CX-Programmer and Citect SCADA. The PLCs are quite old and I was expecting big problems. Workes straight out of the box.
The Adam is quite expensive but is isolated (a big advantage - no chance of ground loops blowing up serial and USB ports), powered from the USB port and has a terminal block connection for RS232/422/485. One at a time of course.
I am going to buy some more plug in terminal blocks and I have all my serial communications sorted in 1 simple unit that works.

ok, I post here my circuit which functions perfectly (convert rs232/rs485)
for those which want to make a simple connection with a cable and without convert,
I board also put the diagram of the cable alone

http://dl.free.fr/niWJn9Qoh

link has been corrupt. Please reup. Thank alot