On Mon, 16 Apr 2007 06:53, you wrote: > On Mon, 2007-04-16 at 04:37 +1200, Rohit Grover wrote: > > Does the experiment require me to connect pins 2 and 3 on the DB9 with > > a short wire? should the DB9 connector be connected to the desktop > > with the pins shorted? > > Just short out the 2 pins on the RS232 connector on the PC side. There > doesn;t need to be anyting plugged in after that. I just use a > screwdriver to short the two temporarily.
Let's be clear, we are testing the functionality of the USB serial adaptor, which is connected to the Apple computer, not the desktop. i.e. connect the USB adaptor to the Apple, load the serial terminal (Zterm), fiddle with the free end of the USB/serial adaptor (probably is a 9-pin D-type male, aka DB9M) and short pins 2 & 3 together. Type something in the serial terminal and you should see the characters you type appear in the terminal window. Make sure 'local echo' is turned off. If 'local echo' is turned on then characters you type are displayed in the terminal regardless. If 'local echo' is turned on and the serial port is not working, then you will see your typed characters anyway. If 'local echo' is on and the serial port *is* working then you will see two copies of the character. If 'local echo' is off and the serial port is not working, then you will see nothing. If 'local echo' is off and the serial port is working then you will see only one character. If you like you can buy a DB9F connector (Dick Smith P2685) and solder a short wire between pin 2&3, then you can plug it into your USB adaptor for testing purposes instead of fiddling with a screwdriver. If this test is successful you will have proved the following: * The USB device is recognised and the driver is loaded and working * You have correctly identified the newly created serial device * Data can be sent out of the transmit pin on the DB9M connector and received on the receive pin HTH, A
