When the UCB scan service returns, register l5 contains one of
the following return codes:
- Return
Code
- Meaning
- 00
- The UCB scan service stored a UCB address in the location specified
in the third word of the parameter list.
- 04
- There are no more UCBs. The UCB scan service set the 100-byte
work area to binary zeros.
Note: - A dynamic device reconfiguration (DDR) swap might occur during
a scan. Because this type of swap results in the interchange of information
in UCBs, it might cause a UCB address to be skipped or returned twice.
- Do not place any dependencies on the order in which the UCB addresses
appear during a scan. The address of the UCB representing device
250, for example, might be returned before the one representing device
140.
- Devices with optional channels are associated with only one UCB.
Therefore, the UCB scan service returns only one UCB address for those
devices. Devices with multiple exposures have one UCB associated with
each exposure. Therefore, the UCB scan service returns one UCB address
for each exposure.