Challenge:
The customer wanted to institute standard revision control procedures on the test program or wirelist for a tightly controlled process. Undocumented changes to a wirelist would not be tolerated in the test process.
Solution:
Two custom scripts were written for the Touch1, comment.cmp and rev_ctrl.cmp. Using these scripts, the supervisor enters the revision history as comment components in the wirelist. A standard part of each wirelist is the CRC signature which is automatically generated by the tester. The CRC signature is displayed in either the Test Cable or View & Change Wirelist buttons in the Main Menu or Test Setup screens. This six digit CRC signature reflects the exact structure of the wirelist including the revision history comments. After the revision history is recorded and the wirelist is verified, the supervisor records the CRC signature and appends it to the wirelist description line when saving the wirelist. If a test is performed and the CRC's do not match, the operator will receive a warning. If the "out of control" parameter is set to "Fail", the test will fail and be recorded as a bad cable. This solution also works with SPC (Statistical Process Control). If SPC data collection is used, an OK will get a zero, a warning will get a one, and a failure will be a two.
Results:
Now, at the supervisor's discretion, an undocumented change in the wirelist will either fail the test or simply warn the operator of the out of revision control condition.
