FEE Control DIM (Distributed Information Management ) as communication layer between TPC/TRD and FEE control/monitoring application at ALICE.

Topics - DIM principle and DIM in FEE Control - DIM Communication - DIM Server / Service - DIM Client - DIM – Data - FEE Command (DIM – Command)

FEE-Controler - DIM-Client Name-Server - DIM_DNS_NODE RCU with µClinux - DIM-Server Register Service Request Service Service Info Subscribe to Service Service Data Commands ALICE (overTCP/IP)

DIM - Communication The client subscribes to a service once and gets back the corresponding data via a callback-function (timed and/or monitored)

DIM - Service: - data (base or complex), the server provides to clients DIM - Server: - the server is represented by servername (must be unique) Server - the service is specified by the servername combined with the servicename (e.g. servername/servicename|type|). - the server can offer several services

Client DIM - Client: - is represented by - has to know servername and servicename to ask DIM – Nameserver for connection point to server. - can send commands to server as base-data-types (like int, char, long, short, float or double) or complex types (like strings or struct-like-objects).

DIM – Data (overTCP/IP) Ethernet-Header IP-Header TCP-Header DIM-Header DIM-Data (Service or Command)

Command ID Payload - Size Flags ( Verify - Flag, ACK - Flag ) ACK - ID Payload. 031 Bits Command as character-string of variable length:

Command With the Command you can do: - Huffman coding to minimize traffic - use payload to transfer data from client to server - use payload to send instructions to server - use to reinstall certain settings after reboot of RCU