IBM System/36 Maintenance Information Manual page 97

7. IBM Cabling System:
Ensure the cable from the IBM Cabling System outlet to the work station is part 6111020 (impedance
matching).
If the Cable Thru feature is present, ensure the cable from the IBM Cabling System outlet to the work
station is part 6111025 (direct connect). Set the terminator switch to the not terminated position and
connect the twinaxial terminator (part 6111028) to port 2 on the work station.
If you want to test a cable that is not attached to a work station, terminate the end of the cable with a
75-ohm resistor assembly as follows:
Phase B
~
$
75 Ohms
Phase A
~
75 Ohms
$
Shield
R368119-0
8. Disconnect the cable to be checked from the system. Connect the alligator clips
II
on the probe to the
end of the cable for each of the following combinations:
a. Ground lead to shield, signal lead to phase A.
b. Ground lead to shield, signal lead to phase B.
c. Ground lead to phase A, signal lead to phase B.
Look at the oscilloscope signal to determine if a cable failure is present. Use the tables and the sample
oscilloscope signals on the following pages to find any problems that are present. The sample
oscilloscope signals shown are for twinaxial cable. IBM Cabling System oscilloscope signals are similar.
Shield
Phase B
R368120-ll
Section 7. Local Work Station Procedures
7-7