having trouble connecting step7 to s7-200

[matgyver]

I’m trying to connect to a S7-200 plc with a pc running STEP7-MICRO/WIN v4.0.0.81 and a PPI to USB cable. This connection worked fine before. But now after the last download (and a few days) the connection will not work. I tried connecting to different ports on either side (pc and PLC). I Even tried a different computer and fresh software. If anyone has any idea what could have change or if there is a way to reset the plc back to factory settings. It would be greatly appreciated

Matt

 

[BryanG]

Taking the 'after the last download' as a place to start, you may have set the port speed to a new value. Make sure you select the 'try all speeds' option on the download page. If that doesn't fix it we need to know what settings you are using as you try to download and maybe some screen shots. You may also want to download the latest version of the software.


Bryan

 

[Ned_Flanders]

This might sound obvious, but check the dil switch settings on the ppi adaptor. Could they have been knocked or has a colleague been "Helpfully" setting them for you!!??

 

[m_turk]

Place the PLC in stop and then try it

 

[falgunvasava]

Are you using your port for some special job?
There are many fuctions like USS protocol where your port is set as free port,in that case you can not communicate to PLC in the run mode since those blocks are being executed,you can switch the plc in stop and then try out.
Baud rate can not be a problem as it supports the maximum supported for S7-200,there are even no dip switches.

Try another cable.
If you are sure about the baud rate then try out cable with com port.
i have faced many problems in usb cable like showing some errors while going online,online editing broken.....etc.

you can reset your plc to factory settings.
get an S7-200 EPROM,copy empty program block,data block and default system block(9.6 baud rate) from another PLC to the EPROM and plug it in your plc.
give a power cycle
Now your PLC has what you had in the EPROM.