Application Note Building
|
| SIUA | |
| TCP/IP Ethernet | Adjacent | |
Application | Signaling | ||
| |||
|
| Point |
Circuit Group 0
[Active]
Circuit Group 1
[Active]
SIUB |
Figure 12. Routing Following Failure of SIUA
The circuit group control will then appear as shown in Figure 12.
The user application software should reset all idle circuits following a transfer, and reset all remaining circuits as they become idle.
When the failed unit recovers, control of the circuits may be transferred back by the application.
Circuit group control is transferred by the application in
two stages. The group should be deactivated from one unit (if communication with that unit is possible) before being activated on the partner SIU. To protect against control being active on both units at the same time, the SIU automatically issues a deactivate command to the partner unit in response to an activate command from the host application and checks the status of each circuit group on the partner unit. An API management event indication is given if dual control is detected.
12
