Defines which address type was used by the transmitter of a message. 
- Enumerator: 
- 
| UCS_AMSRX_RCT_SINGLECAST | Message was transmitted as singlecast.  |  | UCS_AMSRX_RCT_GROUPCAST | Message was transmitted as groupcast.  |  | UCS_AMSRX_RCT_BROADCAST | Message was transmitted as broadcast.  |