TTC WEB PAGETTC UPGRADE HOMENEW SYSTEMTTC RECEIVER CRATERF2TTC SPECIFICATIONSRF_Rx & RF_Tx

 

TTC RECEIVER CRATE

Last updated: 13/12/2006 17:11

 


The TTC receiving crate is part of the project of upgrading the TTC backbone system.

Its task is to replace the TTCmi, receiving the RF timing signals, preparing them for being used by the experiments, and allowing a remote control and monitoring of the main functionalities.

A document summarising the primary specifications of the TTC receiver crate can be found here (28/11/2005). However, more up-to-date information are available on this web site.


Crate description:

Equipment description in experimental areas:

The equipment necessary to receive, convert, clean and transmit the BC and Frev signals will be the same in each experiment and is as described below:

(click on the modules to see the specification of each of them).

 

 

The minimum equipment to be installed in each experiment consists of:

 Each experiment will provide a place to install this receiver crate. One complete system will also be installed in the TTC lab in building 4.

Location:

5 receiver crates will be installed. One in each experiment, and one for development and support, in the TTC lab (4-R-029). 

 

Local

ALICE

RB26

ATLAS

USA15, level-1

CMS

USC55

LHCb

UX85

TTClab

4-R-029

An overview of the locations is available here.


Crate Functionalities

As the previously described VME crate, including the RF2TTC module, will replace 3 previous TTCmi minicrates, it has at least to provide the same functionalities.

Compared functionalities:

 

Functionality

TTCmi

New system

 

 

 

Provided by

Comments

Provided by

Comments

 

Reception

Optical level adjustment

Optical attenuator

 

RF attenuator for CMS

And a comparator at the input of the RF2TTC module

 

Optical reception of encoded BC and Orbit

LHCrx

optoelectrical conversion + amplification

AB/RF Rx

BC and Orbit on separate fibres. Transmitted via SMA connector to the RF2TTC module.

 

Decoding

LHCrx

 

-

No decoding required, but a phase adjustment of the orbit to tune the synchronization. Done by RF2TTC module

 

Internal features

Internal 40.078MHz clock

C. Gen

 

RF2TTC

QPLL in stand alone mode

 

Switch between external and internal clock (manual)

C. Gen

 

RF2TTC

Remotely controlled by a VME register.

 

Orbit digital phase adjustment (manual)

LHCrx

3564 steps of 25ns

RF2TTC

Remotely adjustable by a VME register. Done in the FPGA

 

Orbit pulse stretcher to 1us (fixed)

LHCrx

 

RF2TTC

Remotely adjustable by a VME register. Done in the FPGA

 

BC cleaning (PLL with VCXO)

VCXO-PLL

BC jitter = 7ps rms ensured by a very stable VCXO

RF2TTC

Done by a QPLL

 

 

 

 

 

 

 

Out

Orbit output / ECL

 

 

RF2TTC

2 outputs types (ECL and NIM)

 

BC output / ECL

 

 

RF2TTC

2 outputs types (ECL and NIM)

 

Monitoring

Optoelectrical conversion for signal monitoring with a scope (local)

LHCrx

Physical ECL AC coupled output. Needs a separate optical input.

AB/RF Rx

Lemo output on AB/RF module front panel. (NIM?). Scope (local) monitoring.

 

TTCrx ready (local)

LHCrx

Led

RF2TTC

QPLL lock monitoring and Orbit detection flag. Remotely monitored

 

Presence of optical signal at a correct power level (local)

 

Led

AB/RF

Optical power monitored by AB/RF.

 

Options

Orbit fanout / ECL

TTCcf

optional

TTC Fanout

 

 

BC fanout / ECL

TTCff

Optional typical jitter values at the output = 10ps rms

TTC Fanout

 

 

TDM&BM encoding

TDM BM Encoder

optional

TTCex

 

 

Optical fanout

TTCmx

optional

TTCex/tx

 

 

 

New Functionalities:

New functionalities

Provided by

 

BC phase adjustment

RF2TTC

Not necessary in the previous system. Required to ensure a good synchronisation

Automatic clock switch

RF2TTC

Automatic mode to switch at injection and beam dump. Can be disabled by VME access.

Main BC source selection

RF2TTC

Controlled by VME access. Select BC output between BC ring1, BC ring2, BC ref and Internal BC

Main Orbit source selection

RF2TTC

Controlled by VME access. Select Orbit output between Orbit ring1, Orbit ring2,

Clock and Orbit ECL outputs driven by a 25 Ohms line driver.

RF2TTC, Fanout

 

 

Main


Last Updated by Sophie BARON on 13/12/2006 17:11

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