Hello,

a FM458-1DP sends some diagnostic meassages when you hold the button on the FM while the system is booting.

You can view this with anyterminal program (e.g. Hyperterminal), set communication parameters to19200, 8bit data, even parity, 1 stop bit,no flowcontrol.

Or use the IBS program, I attached:

Copy the fileson a DOS bootdisk (into root), and reboot your PC
ThePC must start from the DOS-bootdisk.
Start the program with "ibs"
Press <alt>
Press <enter>
Press "d"

Press and hold the Button on the FM while repowering the SIMATIC rack.
When the FM is in RUN release the button.

The IBS programm should nowshow some (german) text.

If this fails, one on the serial ports (FM or PC) or the cable is damaged.

The IBS program may work in a DOS-Window under Windows too, but there are PC-configurations that don't work. Therfore you should use DOS for your test.