Anrtisu Cell Master MT8212B, User Manual, Page: 214 / 294

VF Channel Access Testing
The VF Channel Access test feature enables testing on each of the 32 channels of the E1
line. The receive channel is decoded and the VF level and frequency are measured and dis-
played. The signal is also connected to a speaker, enabling the tester to make an audible as-
sessment of the signal quality of the circuit. If the circuit is out of service, the tester can
insert a test tone on the transmit channel for measurement at a remote location with another
test set, or locally with a loopback.
Configuration
Before conducting channel tests, the E1 interface must be properly configured. From the
Setup
menu, select the correct
Framing Mode
,
Line Coding
and
Clock Source
. If the testing
is in-service, the
Receive Input
must be configured for either
Bridged
or
Monitor
modes. The
receive mode should be set up before connecting to the circuit to avoid creating a "hit" on
the customer data. If the testing is in-service, the Cell Master transmit pair should not be
connected to the circuit.
If the measurement is out-of-service, the
Receive Input
mode should be
Terminate
, and the
Cell Master transmitter can be connected to the circuit. The current configuration of the E1
interface is displayed in the status window at the bottom of the screen.
Channel Tests
Once the unit is correctly configured, select the
VF Channel Access
menu to perform tests
at the channel level. Press the
Select Channel
soft key to select specific channels. Either en-
ter a specific channel number from the keypad, or scroll through the channels with the
Up/Down arrow keys. The received VF level and frequency on the selected channel are dis-
played, and the decoded signal is connected to a speaker for audio monitoring. When a test
tone is present on the channel, the level and frequency report will indicate whether the
channel is healthy. If speech is present on the channel, the channel performance can be
judged from the audio quality. A picture of channel utilization can also be formed by
quickly scrolling through the channels.
If the circuit is out-of-service, the user can also connect to the transmit pair and insert a test
tone on the selected channel (note that transmit and receive must be on the same channel).
Two menus enable selection of transmit level and frequency. The frequency can be entered
from the keypad, or scrolled to common test frequencies (404 Hz, 1004 Hz, 1804 Hz, 2713
Hz, and 2804 Hz) with the Up/Down arrow keys. To check the performance of channel
level equipment, the test tone can be measured at a remote location with another VF chan-
nel test set.
Chapter 10 E1 Measurements
10-11