Siemens s7-200 Communication problem

Hi, new member here - hope someone can help me with this one. Having trouble with PC/PPI (USB) cable. Error message reads:

Error: Communications time out.
Check port number and network address, baud rate and the attached cable.

Tried all available combinations of above (I think) but still having no luck - any help would be much appreciated

Reply number 9 in this thread may help.
http://www.plctalk.net/qanda/showthread.php?t=54966&highlight=s7-200

Bryan

if your pc have serial port and usb port both,you should select usb on setpg/pc option.

Check to make sure you have selected the correct driver

Microwin --> PC/PPI cable (PPI)

then select USB from properties.

You should be plugged into your PLC when you set this up.

Thanks everyone for your help. The initial problem was with the driver - it had not installed correctly, but I found one on the web. Once this was sorted, I identified the correct com port. Once the correct com port was identified, I attempted communicating with the PLC again - PLC was not identified, but UNKNOWN(!!??) was identified at address 2. PLC is on in run mode (have also tried with PLC in stop mode) with no I/O connected. Any further assistance would be greatly appreciated.

I don't remember having seen the UNKNOWN message, what versions of MicroWin and PLC are you using? Also as you have been 'adjusting' the comms cable switches what are those set to?

Bryan

You will get "UNKNOWN" Plc if you use adapter with old firmware version, with newer PLC.

The RS232 / PPI cable works with even the older plcs, the USB version doesn't work with the older S7 200, S7 21X series.

CPU is 224 (214-1AD23-0XB0), software is Step 7-Microwin 3.2 + SP4. I had initially specified com port 3, but later found correct port was com port 6 (driver that came with the cable did not install properly). If the problem is with the compatability between cable and PLC, what are my options? Hope someone can help. Thanks.

Maybe Your software is problem, too old for S7-224. The latest version is V4.0 + SP7.
Also, Your adapter must be 'electronic version 05', as I recall.

Try to open new project, to see if You can select CPU 224 FW version 2.0 or 2.1. If not, update Your software (and adapter).

This is why I hate SIEMENS. See photo, what I must have, to connect to S7-200 (from left to right)
1. RS232/PPI adapter, E-stand 04: to connect to S7-22x using Step7 MicroWin V4.0 and later. Work fine with PC with COM port, but using USB/232 adapter, problems...
2. USB/PPI adapter, E-stand 05: to connect to S7-22x using Step7 MicroWin V4.0 and later. Work fine with PC with USB port, but You can not connect any serial device to S7-2xx using this adapter
3. RS232/PPI Isolated adapter, old one: to connect to S7-21x using Step7 MicroWin V3.x and earlier. Work fine with PC with COM port, but using USB adapter, problems... And also You can not connect to S7-22x
4. PC adapter, (MPI/DP/Profibus): to connect to S7-22x using Step7 MicroWin V4.0 and later. Work fine with PC with USB port, but ONLY if You first connect with cable 1 or 2. Why? Because this PC adapter work at minimum baudrate 19,200, and S7-22x ports are factory set to 9,600 so You can not connect berofe You use cables 1 or 2 to change port speed.. TERRIBLE SIEMENS. You pay 1500$ ONLY for adapters, and still have problems.

For example, for OMRON all You need is homemade (2$ cca) cable to connect to ANY PLC and ANY HMI.

Thanks Homer - i have just organised a software upgrade to V4.0. will try this before spending more $$$ on cables.

Hello All,

I am trying to connect to the cpu of a S7-200 through a USB to Rs232 cable. I am using Step7 Micro/Win Version 4.0 with a service pack 9. It is a S7-200 CN with a 224CN CPU. I had problems with my ports at first, now i have that under control. However now that i have the corect ports assigned, it keeps giving me an error of RPC server unavailable. do any of you know what this could be? can any of you give me some ideas? this is my first time using step 7. im use to RS Logics or Automation direct products.
I am trying to view and save the program from a working logic controller to have the program as a backup. Thanks

Maybe I'm interpreting your post wrong, but you can't use a standard usb/rs232 cable to communicate with the controller, you need one of the Siemens cables.