I have been trying to test my USBMOD3 datalog link by trying to do a loopback test. I've wired up the module in the following way:
Pin 4 (Vcc) is hooked to Pin 8 (Reset In) since an external device doesn't need to reset the device.
Pin 9 (Enumeration Power) is hooked to Pin 10 (Reset Out) for bus powered operation per the user's manual.
Pin 18 (Power Control) is wired to ground to select bus powered operation per the user's manual.
Pin 23 (Data Set Ready) is hooked to Pin 24 (Data Terminal Ready) for modem control handshaking.
Pin 25 (Clear To Send) is hooked to Pin 26 (Request To Send) for modem control handshaking.
Pin 27 (RxD) is temporarily hooked to Pin 28 (TxD) for a loopback test.
I'm running WinXP on an IBM TP40.
I have a very ricey USB cable that has blue LEDs that light up when the USB port is powered.
Win XP recognizes the USB serial port when it is plugged into a USB port. the lower USB port is mapped to COM4: and the upper USB port is mapped to COM5:
Device manager says the USB serial port is working correctly, and that the FTDI driver version is 1.0.2154.0, dated 4/16/2004. Per the FTDI web sire, this is the latest driver.
When the converter is plugged into either port, the blue lights comes on.
I bring up hyperterminal and point it at the appropriate COM port. When I do this, the blue lights in the USB cable go out.
If I try to exit hyperterminal before typing any characters to do a loopback test, hyperterminal will prompts me if I am sure I want to quit. When I say yes, hyperterminal closes and the blue lights come back on.
If I try typing some characters to do the loopback test, nothing happens on the hyperterminal screen. After that, if I try to close hyperterminal, I get the prompt asking if I am sure. When I click ok, I get an hourglass cursor on the hyperterminal window for ever, with the lights staying off.
When I click on the upper right hand X to close the window, I get the "This program is not responding" popup window. If I click "End now", it goes back to the hourglass. The hyperterminal window does not go away until I unplut the USBMOD3 from the USB cable. At that point the blue lights come back on.
Any ideas as to what is wrong and/or how I might debug this?