The ACB-764 Annunciator Control Board allows for the maximum of 64 switch indicator groups to be controlled and monitored. These groups are located on the sub-modules DCM-8 Display Control Module and the AMB-8 Annunciator Monitor Board. The ACB-764 along with its sub-modules DCM-8 and AMB-8 are UL Smoke Control Listed for controlling fans and dampers. The ACB-764 and AMB-8 can also be used as a LED annunciator drivers. A seven-segment diagnostic LED is provided for troubleshooting.