Subject:
ADF->TAB working!
From:
Michael J Mulhearn <mulhearn@nevis.columbia.edu>
Date:
Thu, 7 Apr 2005 19:22:12 -0400 (EDT)
To:
Jaroslav Ban <ban@nevis.columbia.edu>
CC:
Daniel Edmunds <edmunds@pa.msu.edu>, laurens@pa.msu.edu, Hal Evans <evans@nevis.columbia.edu>, "'Linda Bagby'" <bagby@fnal.gov>, "'Alan L. Stone'" <alstone@fnal.gov>, "'Sabine Lammers'" <lammers@fnal.gov>, Nikos Varelas <varelas@uic.edu>

Hello!

The ADF is talking to the TAB!

For this test, the ADF transmits 0x55 for EM towers and 0xaa for Hadron towers on every event, the TAB is pulsed and the raw test memory read out.

Here's what it receives:

0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
0x0 0x0 0x0 0x0 0x0 0x0 0x55 0x55 0x55 0x55
0x55 0x55 0x55 0x55 0x55 0x55 0x55 0x55 0xaa 0xaa
0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa 0xaa
0x0 0x0 0x0 0x0

Ta Da!

As has been noted, the ADF->TAB cables do not fit the ADF P0 connector properly.  Filing down the connector polarity key (as Dan did for the SCL fanout) and inverting it did the trick.  The non-sensical results before (which looked like a synchronization problem!) were because the frame bit indicating the least significant bit was exchanged with a data channel!

The problem was simple, but took a while as this was a learning experience for me.

We still need to reconsider these cables.  Now that I have a working example in front of me, I'm much more confident to discuss polarity issues with the new cards as well.

Next I will do some more tests of synchronization before tackling the pseudo-random data tests.

cheers,
mike