MB300 communication with CI855 and AC800M
In addition to Rob's answer - look the manual AC800M Communication Protocols 3BSE035982-510:
"The CIPos parameter specifies the position number of the CI855 unit in the hardware tree (identical to its position on the CEX bus). CAPos specifies the MB 300 network number, and NodePos the node position of the controller on the network."
I think you have wrong CAPos and Nodepos in MB300Connect block - there you should put the valid data for AS450 node's settings. Also look the settings of your CI855 in HW configuration - here you set network and node number for CI855. it has to be in the same network (11) with AC450 but with the unique node number. Also check MB300 protocol type and other settings.
In order to test your received data, in Online mode try to set Rd parameter of Receive block to a different value. In case it is overwritten by the other value, then the received values are coming from MB300 node.