Honeywell HPM, Service

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4 Fault Isolation
4.10 HPM Alternate Private Path
R688 HPM High-Performance Process Manager Service 379
December 2020 Honeywell
Step Action
6
Connect a standard Redundancy cable (Honeywell part number 51201667-100 or -200,
revision B) between the Debug ports of the two HPM Comm/Control cards. To minimize
the probability of disturbing other cabling, it is preferable not to disconnect the
backpanel Redundancy cable for this procedure; however, the backpanel cable can be
used if it is the only revision B cable available.
The connectors will fit, but the latches on the cable will not engage. This is normal.
7
It is planned that a future software release will detect the presence of the Alternate
Private Path connection and indicate a soft failure. If this feature is implemented, each
card will indicate a soft failure code of 50 (“ALT REDUN CABLE APPLIED” on a US,
UX
S, or GUS display, or “SF50” on the HPM Comm/Control card’s Alphanumeric
display) as soon as the cable is connected. This is expected.
See Note 1.
8
Load the secondary HPMM from a US, UXS, or GUS, and wait for it to synchronize.
When the operation has completed successfully, the secondary HPMM status should
display BKUP.
9
From the US, UXS, or GUS, command a swap. Do NOT power down the primary
HPMM.
10
Wait for the two HPMMs to resynchronize (about 6 seconds).
11
From the US, UXS, or GUS, command the defective HPMM (now operating as
secondary HPMM) to shut down.
12
Remove the cable between the two Debug ports and reinstall the protective boots, if
any.
13
Close both Debug Panel doors.
14
Verify that the standard redundancy cable is properly connected to both HPMM
backpanels.
15
Replace the defective HPM Comm/Control card by using the procedure in subsection
“HPMM and IOP Cards” (“Removal and Replacement” section).
16
From the US, UXS, or GUS, load the HPMM in which the Comm/Control card was
replaced. There should be no soft failure indication for either HPMM controller.
17
Wait for the repaired HPMM to synchronize. At this point, normal HPMM redundancy
operation is restored.
Note 1
The soft failure indication does not appear with the currently released version of the software, but the
Alternate Private Path will work correctly. If future releases check for the presence of the Alternate Path
connection, the soft failure will only appear if both the HPM COMM/Control card and Debug cable
revisions support the Alternate Private Path. This indication serves several purposes.

The soft failure provides conformation, both on the local Alphanumeric display and the console that
the board has recognized the connection of the cable and has switched the Alternate Private Path.

If the software checks for the Alternate Private Path connection, the absence of a soft failure alerts
the technician to verify the revision of the HPM COMM/Control card and the Redundancy cable.

If someone attaches the Alternate Private Path cable to the normally operating HPMM controller, the
action will be journalized.