Determining Your Problem Category; Adding The 5500 Control Unit To Existing Twinax Cable Runs - IBM 5500 Operational, Installation, And Maintenance Manual

Determining Your Problem Category

Figure 38: Problem Category Procedures
Categories
A B C
2 2 1
4
3 3 3
6 9
4
5
6
5 7 4
1 1 2
8

Adding the 5500 Control Unit to Existing Twinax Cable Runs

Decide the category of your problem (A, B, C, or D) and follow the
instructions in the order shown in the category column.
A - New or changed installation with a solid problem.
B - New or changed installation with an intermittent problem.
C - Unchanged installation with a solid problem.
D - Unchanged installation with an intermittent problem.
D
Ensure that terminals have no internal hardware failures or known
1
problems.
Check for a valid twinax installation cable length, routing, number of
5
connections.
Check cables for opens and shorts. Refer to "Step-by-Step Cable
3
Debugging" on page 105.
Check for Ground Potential Difference problems. Refer to "Step-by-
9
Step Cable Debugging" on page 105.
Check all cables for correct phase connections. Refer to "Step-by-Step
Cable Debugging" on page 105.
Check for the presence of AC noise. Refer to "Step-by-Step Cable
6
Debugging" on page 105.
Use TDR to analyze signal quality. Refer to "Advanced Time Domain
8
Relfectometry (TDR) Procedure" on page 113.
Ensure the 5500 twinax controller card is functioning correctly and
4
within specifications.
Visually check the entire twinax run for good wire connections. Refer
2
to"Step-by-Step Cable Debugging" on page 105.
Perform a ground loop impedance test on all the terminals. Disconnect
7 the twinax cabling for this test. Refer to "Step-by-Step Cable
Debugging" on page 105.
When upgrading from an older twinax workstation controller to a newer
workstation controller (such as the IBM 5500 Control Unit), the performance
Description of Check Task
101