The purpose of this resolution is to identify which Hot Standby (HSBY) modules are used with the 984 Chassis Mount PLCs and which are used with 984 Slot Mount PLCs.

AM-S911-000 and AM-R911-000 HSBY option modules are for use with the 984 Chassis Mount PLCs only. They will not fit into a 984 Slot Mount backplane.
The AS-S911-800 is for use with the 984 Slot Mount PLCs only. It will not fit into a 984 Chassis Mount housing.

The AM-S911-000 was the first HSBY module for 984 Chassis Mount configurations. This module was redesigned to improve system reliability and the new version designated AM-R911-000. The AM-S911-000 and AM-R911-000 are not compatible and can not be interconnected. A 984 Chassis Mount HSBY system must contain either AM-S911-000 modules or AM-R911-000 modules.

There is only one version HSBY module for the 984 Slot Mount PLCs, ie: AS-S911-800.