I'm still trying to hook up my ASR-33 to my Altair clone. I've got a new current loop connect for B&B Electronics and they say it's ideal for this application. Trouble is knowing what to connect to what. On the cable from the ASR-33 I have:
Red wire TTY send
Black wire TTY send
White wire TTY receive positive
Blue wire TTY receive negative
On the converter I have on the left side terminals for:
TD
RD
10-30VDC
GND
and on the converter I have on the right side terminals for:
T+
T-
R+
R-
Current GND
Current GND
I've connected it like this:
Red wire to T+
Black write to T-
White wire to R+
Blue wire to R-
Pin 2 from Altair serial port to TD
Pin 3 from Altair serial port to RD
Unsheathed GND from Altair serial port to GND
Positive from a 20VDC power supply to 10-30VDC
Negative from a 20VDC power supply to GND (NOT Current GND)
Wired like this, the ASR-33 just chatters away cycling the print hammer but not printing anything (like it does when it has no current loop connection). I've also tried connecting Pin 7 from the Altair serial port to GND on the RS-232 side of the converter (instead of the unsheathed GND from the Altair to GND on the RS-232 side of the converter) and connecting the negative side of the 20VDC power supply to Current GND on the current-loop side of the converter instead of connecting it to GND on the RS-232 side of the converter (and I've done the permutations of this).
All to no avail. Can anyone see what I'm doing wrong?
Gabriel Egan