Hello! Here you are some test results:
Do you have an oscilloscope or a voltmeter?
voltmeter FLUKE 187
If you connect an LED with a 1K resistor in series, between TX and GND, does the LED blink?
If you connect an LED with a 1K resistor in series, between RX and GND, does the LED blink?
Yes both, but only with the RS232 connected to pc. If the RS232 is not connected there are no volts between GND and Rx or GND and Tx.
Have you "pinned-out" the Comeau/Hanna connector?
I attach some pics. I confirm you the schematic I attached in my last message.
As I posted (Reply #3), there must be a combination of E and D that will trigger the instrument to output data.
You would have to work out the handshaking later, but if you "trick" it first that would be progress.
I checked many times, E seems not to enter on my PCB, and doesn't seems to be connected with anything else.
Can you confirm that if you configure Hyperterminal's Flow Control for "None" there is no data?
I tried both solutions. I have incoming data in hyperterminal with "hardware" flow control and also with "none" flow control.
