G-Link Output Measurements

Date Tests Info

18-Aug-05 TAB to L3 transmission using special VRB firmware

250M events transmitted w/out error

BER < 8x10^-12

here

05-Aug-05 TAB to G-Link Receiver Test Card w/out errors

ran at 75.8 kHz L1Accepts for ~4 hours

normal L2/L3 headers and trailers with fixed TT data (mostly 0)

no parity errors detected in any 16-bit data word

BER < 10^-12

29-Jul-05 TAB to L2 transmission w/out errors

ran at 6 kHz for ~1/2 hour

BER < 10^-9

25-Jul-05 First GAB to L2 tests done

No loss of lock observed

No protocol or data errors observed on FIC

20-Jul-05 Apparent g-link sync (and VTM protocol) errors turn out to be a red herring. here

11-Jul-05 Measurement of total jitter in TAB g-link output at Nevis.
Note: this measurement should be treated with care. What is really needed is a true BER measurement using a g-link reciever. For that we need the G-Link receiver test card though...

total jitter from meas = 130 ps

jitter of (electrical) data output to optical transmitter on TAB measured wrt transmission clock

measurement triggered only on real data transfer (DAV)

random test data (different for each event) sent out from TAB

timing from local oscillator on VME/SCL card

measurement made using special jitter measuring software on an Agilent digital scope - here

here

07-Jul-05 Status of transmission errors from Fermilab

TAB to VTM (on VRB) transmission runs for hours without loss of sync (or any other VTM error) when sending fill frames (after reseating SCLR and fixing software)

Sync error occurs after ~1000 L1 Accepts when sending test data from TAB

10-May-05 Mikolaj Cwiok's measurement of errors on data transmitted to L2Beta at Fermilab.

this is where the 1e-4 BER estimate comes from

here

Jan-05 Measurements of G-Link Sync using simple G-Link Recever card at Nevis hooked up to output of TAB.

never observed loss of lock when transmitting test data from the TAB
timing from local oscillator on VME/SCL card through standard path

Jan-05 Measurements of jitter (and its frequency spectrum) on optical output of TAB and GAB boards at Nevis.

continuous test data transmission on g-link from TAB and GAB

compare transition point of data ~1us after reference data transmission with expected time

here

Date	Tests	Info
18-Aug-05	TAB to L3 transmission using special VRB firmware 250M events transmitted w/out error BER < 8x10^-12	here
05-Aug-05	TAB to G-Link Receiver Test Card w/out errors ran at 75.8 kHz L1Accepts for ~4 hours normal L2/L3 headers and trailers with fixed TT data (mostly 0) no parity errors detected in any 16-bit data word BER < 10^-12
29-Jul-05	TAB to L2 transmission w/out errors ran at 6 kHz for ~1/2 hour BER < 10^-9
25-Jul-05	First GAB to L2 tests done No loss of lock observed No protocol or data errors observed on FIC
20-Jul-05	Apparent g-link sync (and VTM protocol) errors turn out to be a red herring.	here
11-Jul-05	Measurement of total jitter in TAB g-link output at Nevis. Note: this measurement should be treated with care. What is really needed is a true BER measurement using a g-link reciever. For that we need the G-Link receiver test card though... total jitter from meas = 130 ps jitter of (electrical) data output to optical transmitter on TAB measured wrt transmission clock measurement triggered only on real data transfer (DAV) random test data (different for each event) sent out from TAB timing from local oscillator on VME/SCL card measurement made using special jitter measuring software on an Agilent digital scope - here	here
07-Jul-05	Status of transmission errors from Fermilab TAB to VTM (on VRB) transmission runs for hours without loss of sync (or any other VTM error) when sending fill frames (after reseating SCLR and fixing software) Sync error occurs after ~1000 L1 Accepts when sending test data from TAB
10-May-05	Mikolaj Cwiok's measurement of errors on data transmitted to L2Beta at Fermilab. this is where the 1e-4 BER estimate comes from	here
Jan-05	Measurements of G-Link Sync using simple G-Link Recever card at Nevis hooked up to output of TAB. never observed loss of lock when transmitting test data from the TAB timing from local oscillator on VME/SCL card through standard path
Jan-05	Measurements of jitter (and its frequency spectrum) on optical output of TAB and GAB boards at Nevis. continuous test data transmission on g-link from TAB and GAB compare transition point of data ~1us after reference data transmission with expected time	here