Unblanking Functional Diagnostic

1 Diagnostic Link

Diagnostics >> System Function >> RF >> Unblanking Functional Diagnostic

Diagnostics >> Hardware Location >> System Cabinet >> RF >> Unblanking Functional Diagnostic

Figure 1. Unblanking Functional Diagnostic

2 Purpose

UNBLANK, UNBLANK2, EFB and EFB2 are played out at different duty cycles so you can verify that these signals are being generated by exciter.

3 Components Tested

  • AGP board

4 Requirements

  • AGP board

  • Oscilloscope

5 Test Sequence

  1. Remove the cable from the Exciter Front Panel's J15 serial connector.

  2. Click Run.

  3. Probe each pin of the J15 connector with a short piece of wire such as a paper clip and connect the probe to the wire to get a reading (see Figure 2).

Figure 2. Exciter Front Panel, J15 Connector

6 Expected Results

Each pin should have a reading as noted below.

  • UNBLANK will be a 10µS pulse every 70µS.

  • ENVFBK will be a 20µS pulse every 70µS.

  • UNBLANK2 will be a 30µS pulse every 70µS.

  • ENVFBK2 will be a 40µS pulse every 70µS.

  • The xxx_P signals are inactive at 3.3 volts and active at 0 volts.

  • The xxx_N signals are inactive at 0 volts and active at 3.3 volts.

    note:

    Cycle Tolerance = +/- 2µS