CHAPTER 4: Test Procedures
4.3 Check Power
Some (not all) ISDN terminals require power from the S/T interface.
This procedure verifies that power is received properly at the S/T interface. See Figure
1.Put the circuit in Test Configuration 1.
2.Make sure the Test Set is in NORMal mode; LINE button should be out.
3.If the terminal requires Phantom Power (see terminal user guide) use the following table:
Phantom |
| Conclusion |
Light |
| |
|
| |
Green |
| Power OK |
Red |
| TX & RX pairs reversed |
|
|
|
None | No power being received | |
|
|
|
4.Certain terminals use what is known as PS2 power, which is delivered on pins 7 and 8. If your terminal uses PS2 power check the AUX light and use the following table:
AUX |
| Conclusion | |
Light |
| ||
|
|
| |
Green |
| AUX power OK | |
|
|
|
|
Red |
| Pins 7 & 8 reversed | |
|
|
|
|
None |
| No PS2 power being received | |
|
|
|
|
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