Preliminary Settings
Before attempting to adjust the input/output levels, configure them to the setting shown in the following table.
| Application | Input Level Setting | Output Level Setting |
| PBX Trunk (E&M) | -2 | 2 |
| PBX Station (FXO) | 2 | 0 |
| Key Telephone Systems (FXS) | -3 | 2 |
Checking the Operation of the PBX Station
This procedure is used to verify that the losses across the PBX, in a PBX station application, are within acceptable limits for operation with the voice network.
- Use the test setup shown in the following figure. Initially, set both Voice Network Analyzers (VNA) to BRDG, TEST and OFF. The PBX station numbers in the figure below are fictitious, used here for reference only.
- Lift the calling telephone set off-hook, wait for the dial tone and dial station 5678. The receiving telephone will ring.
- Place the SETUP switch on the receiving Voice Network Analyzer to TERM. The telephone will stop ringing.
- Place the SETUP switch on the calling Voice Network Analyzer to TONE, and disconnect the calling telephone from the Voice Network Analyzer.
- Observe the displayed value on the receiving Voice Network Analyzer. It should read between -5 dBm and -8 dBm. If the level is outside of this range, the PBX should be checked for proper operation by authorized service personnel.
