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

DIM @ ALICE (overTCP/IP)

DIM - Communication

The client subscribes to a service once and gets backthe 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 PID@hostname

- 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 orCommand)

Command

ID

Payload - SizeFlags (Verify - Flag, ACK - Flag)

ACK - IDPayload

.

.

.

0 31 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