NRAO Home  >  Green Bank  |  Wiki Topic:    GB > Software > TWikiUsers > FrankGhigo > MyObservingIssues > ModificationRequest10C505

Changes | Index | Contents | Search | Statistics | Go

IF Rack: Change messages to indicate non-balance and non-linearity.

back to balancing overview

MelindaMello -- Are these messages intended to be generated by the Balance API?

1. Introduction

The IF Rack power detectors are normally set to nominal values of 1 to 3 volts. If power levels are far outside these ranges, the V-F detectors and ODM amplifiers may be outside their linear range. T.Minter and Steve White have investigated the linearity of the V-F detectors and the ODM (reference GBT Memos 241 and 242). Using the data from these memos, we have distilled simple criteria for "notice" and "Warning" messages.

2. Background

The present messages from the IF Rack are as follows

• Error message for IF Rack voltage > 9.99 volts
• Notice message for voltage = 0
• Warning message if the balance operation cannot get within 0.5 db of the target level.

This MR is part of a series of MRs aimed at creating a production Balancing API in Python. For more information regarding this effort, please refer to the BalancingMetaMR.

3. Requirements

The proposed new criteria are as follows:

• Notice message if balance cannot get within 0.5 db of target level.

• Warning if voltage < 0.02 v ("Warning: no IF power in IF channel nn")

• Warning if voltage < 0.1v or > 8 v ("Warning: IF power may be in non-linear range, channel nn")

• Notice if 0.1 < V < 0.4 or 5 < V < 8 ("Notice: IF power in slightly (1-2%) non-linear range, channel nn")

The criteria will be read from a configuration file, so that future changes may be easily made without any software work.

4. Design

5. Deployment Check List

6. Test Plan

Critical!! ChangeControlCommittee will be reviewing these.

Don't forget to include/acquire any additional GBT test time needed outside integration/regression testing! Get your requests in early!

Important! If possible, you should conduct as many of your tests as possible in offline modes and/or with a simulator. We should constantly endeavor to minimize our use of telescope time for testing!

7.1 Internal Testing

This section covers things like unit testing, simulator testing, and any other tests required to make sure this MR is ready for sponsor/integration/regression testing.

7.2 Sponsor Testing

Test 1.

• Record the tolerance level.
• Change the tolerance to .001.
• Balance the IF Rack via cleo.
• Verify that a message is generated warning that it could not get within .001 of the target level
• Change the tolerance level to the original value

• Record the low voltage level.
• Change the low voltage level to 10.
• Balance the IF Rack via cleo.
• Verify that a message is generated: "Warning: no IF power in IF channel nn"
• Change the low voltage level to the original value

• Record the non linear low voltage level.
• Change the non linear low voltage level to 3.
• Change the targe level to 3 volts
• Balance the IF Rack via cleo. If needed, subtract 1db to the attenuators to ensure the detector values are < 3
• Verify that a message is generated: "Warning: IF power may be in non-linear range, channel nn"
• Change the non linear low voltage level to the original value

• Record the non linear high voltage level.
• Change the non linear high voltage level to 3.
• Change the target level to 3 volts
• Balance the IF Rack via cleo. If needed, subtract 1db to the attenuators to ensure the detector values are > 3
• Verify that a message is generated: "Warning: IF power may be in non-linear range, channel nn"
• Change the non linear high voltage level to the original value

• Record the slightly non linear low voltage level.
• Change the slightly non linear low voltage level to 3.
• Change the target level to 3 volts
• Balance the IF Rack via cleo. If needed, increase attenuators to ensure the detector values are < 3
• Verify that a message is generated: "Notice: IF power in slightly (1-2%) non-linear range, channel nn"
• Change the slightly non linear low voltage level to the original value

• Record the slightly non linear high voltage level.
• Change the slightly non linear high voltage level to 3.
• Change the target level to 3 volts
• Balance the IF Rack via cleo. If needed, increase attenuators to ensure the detector values are > 3
• Verify that a message is generated: "Notice: IF power in slightly (1-2%) non-linear range, channel nn"
• Change the slightly non linear high voltage level to the original value

7.3 Integration/Regression Tests

What do the integration/regression testers need to do in order to test this MR.

Signatures

APPROVED: I acknowledge that my request is fully contained in this MR, and if the SDD delivers exactly what I specified, I will be happy.

ACCEPTED: I acknowledge that I have validated the completed code according to the acceptance tests, and I am happy with the results.

Written	- FrankGhigo - 12 May 2006
Checked	- MarkClark - 01 Jun 2006
Approved by Sponsor	- FrankGhigo - 02 Jun 2006
Approved by CCC	symbol - product/version - date
Accepted/Delivered by Sponsor	symbol - product/version - date

Symbols:

• Use %X% if MR is not complete (will display )
• Use %Y% if MR iscomplete (will display )

CCC Discussion Area

-- FrankGhigo - 12 May 2006