[HECnet] SC-40

[Johnny Billquist]

On 2015-02-12 20:12, Cory Smelosky wrote:


Sent from my iPhone

On Feb 12, 2015, at 14:09, Peter Lothberg <roll at Stupi.SE> wrote:

Depending on config of the system chasseie ground and signal ground
might be isolated.

The only ground connected is shield ground. ;)

That is just plain wrong.

If there is a "klinik" (another DB25 port, or if it has DB25's for
user terminals (check if there is a board connected on the able)
measure from pin 7 to pin 7 in another connector.

  Pin 7 is NCL on all the serial breakouts I have.

Huh? Pin 7 on a DB25 RS-232 is signal ground. It is one of the three pints you actually need. The other two being pin 2&3. No other pin is required, but 2,3,7 are the ones *absolutely* required.

And for a null modem cable, you connect:

2-3
3-2
7-7

	Johnny