TB820 related problems with start up of analog S800 I/O modules after hot plug or power up
- Upgraded firmware on modules. Some Workarounds available
The problem is fixed on following PR of listed modules.
AI810 3BSE008516R1 PR:H
AI820 3BSE008544R1 PR: D
AI830 3BSE008518R1 PR: C
AI835 3BSE008520R1 PR: E
AO810 3BSE008522R1 PR: D
AO820 3BSE008546R1 PR: D
If the problem shows at an "hot plug" operation, the module can be brought into service by repeated lock/unlock operations.
TB820 power up
If the problem shows at power up of a TB820 due to local power out, repeated on/off switching of the TB820’s power supply or repeated module lock/unlock operation will bring the cluster’s I/O modules into service. Using a centralized power supply for CI810/PM810 and its connected TB820s, the problem is eliminated. Powering the TB820 clusters from the same power source is recommended to keep availability up and to avoid optical link communication breakdown due to a cluster local power down.
An I/O cluster I/O field circuit can be powered from a separate power source to reduce the load of a centralized power supply without causing this problem as described.
[ref SR8056 VASMASOITA0016 ]
- Module start-up problems
Tests have shown module start-up problems when an S800 analog module is "hot plugged" to the Modulebus or at power-up of TB820. Analog modules will sometimes not be recognized by the system, when the module lock is turned in "locked" position following a "hot plug" operation or after power-up. The problem does not show at power-up (switching the 24V supply on) in configurations where the PM/CI810 and TB820s are powered from the same 24V supply. If an TB820 I/O cluster is powered from a separate supply, switching the 24V supply on with an already running PM/CI810 can give start-up problem for analog modules. The problem does not apply to digital modules in any configuration.
So far, the problem has not been reported from the field.
- Modulebus frame clocking scheme
With the introduction of TB820 Optical Modulebus modem and CI820 Redundant FCI, a new Modulebus frame clocking scheme was introduced.