at_lnk

Overview

The at_lnk.py acceptance test checks the error rate of the QIE card's data links.

Procedure

To run this acceptance test, run

python at_lnk.py -t [teststand_name] -n [n_reads] [-v]

where [teststand_name] represents the name of the teststand as recorded in teststands.txt (the default is 904at), [n_reads] is the integer number of groups of 100 BXs that will be analyzed, and [-v] is used to turn on verbose mode.

Results

Each time you run the test, the following items are written to the data/at_results/[unique_id]/at_lnk/yymmdd_hhmmss directory:

• yymmdd_hhmmss_lnk.png - An image containing the following:
  • A histogram of each link's link pattern test error rate. The red filled section indicates errors in the string pattern and the unfilled orange histogram indicates counter errors.
  • A histogram of each link's link error rate as read by the uHTR.
• yymmdd_hhmmss_lnk.root - A ROOT file containing the above histograms.

Analysis

A good board should say something like the following at the end of the test:

====== SUMMARY ============================
Teststand: 904at
QIE card: 0x67000000 0x9b32c370 (crate 2, slot 2)

(1) Link pattern test:
BXs read out: 100
[OK] There were no errors!

(2) uHTR link test:
BXs read out: 100
[OK] There were no errors!
===========================================

and the plots should be completely green.

A bad board will say something like this at the end:

======= SUMMARY ============================
Teststand: 904at
QIE card: 0x67000000 0x9b32c370 (crate 2, slot 2)

(1) Link pattern test:
BXs read out: 100
[!!] Errors:
	* Link 18: error rate = [0.90, 0.89]
	* Link 20: error rate = [0.90, 0.89]
	* Link 23: error rate = [0.90, 0.89]

(2) uHTR link test:
BXs read out: 100
[!!] Errors:
	* Link 23: error rate = 1.9e-09
===========================================

and there will be red and/or orange in at least one plot.

More details:

• The orange line on the left histogram means things are bad!