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Tester 297 - Protocol

I'm going to make a lead which will allow me to connect to a logic analyser.
Ive got a serial lead with 1 male and 1 female connector

 PCB markov               ov            +              +       o/p i/p
 pcb number 21 20 19 18 17 16
 cable colour white brown yellow pink grey green
9 pin plug 3 8 5 7 4 9

 orange white green grey yellow black

Below are the two ends of the serial lead im going to make the test lead from

Because there are 2 ov connections I'm not sure which cable to use as GND for the logic analyser.

It could be that the payphone detects the presence of the tester 297 when pin 3 and pin 8 are connected together.
They are shorted at the tester, but i dont know what happens at the payphone.

Measuring with an ohmeter back into a CT25 pins 3 and 8 do seem to be commoned, but they seem to be around 4.5 ohms from GND on the pcb.

Pin 5 and 7 do not seem to be commoned.

ebay 8 channel logic analyser

Note: This logic analyzer requires a PC with a high-speed USB 2.0 interface.

Support the following systems: support WINXP/2000, WIN7, VISTA, LINUX

 The performance of Saleaa8 is different from that of salesaa16. The number of channels is 8 and the speed is up to 24M. The video software usage can be referenced but not the same.

Shipping packing list:
1, 24M 8CH logic analyzer host 1 unit.
2, color DuPont line 10 lines (10 different colors) 10 pieces.
3, high quality USB-MINI line (NOKIA dedicated line) 1 piece.

Product size: 50mm X 28mm x 14mm

Sample speed up to: 24 MHz

The sampling speed of each channel of the logic is 24M/sec. The general application is about 10M, which is enough for various occasions.

test lead and logic analyser