Tektronix CTS 850, User Manual

Page: 109 / 178

Basic Test Procedures
CTS850 SDH/PDH Test Set User Manual
3–3
2. Set up the CTS850 as follows:
Press Menu
Button Select Menu
Page Highlight
Parameter
Select Choice
TEST SETUPS RECALL
INSTRUMENT
SETUPS DEFAULT
FACTORY
SETTINGS Recall Setup
TRANSMIT TRANSMIT
SETTINGS Transmit Rate STM-1E
3. Press the AUTOSCAN button. The receiver locks onto the output
from the NE, displays the signal structure, and shows information
about the content of AU #1.
4. To analyze the payload pattern, select Show Payload. The
CTS850 detects a PRBS of length 2
23
–1.
5. Check the J1 Path Trace for any message.
6. Check the front-panel status lights to verify that there are no
errors, alarms, or failures.
7. Select EXIT to leave the AUTOSCAN dialog box.
Transmission Signal Quality Testing
Measuring Bit Error Rate
The bit error rate (BER) test is one of the best ways to measure the
quality of an SDH transmission link. You can use the CTS850 to
make a BER test on a two-way link that is connected in a loop-back
configuration. If this is a test you perform often, save it as a pass/fail
test for easy recall.
1. Connect the CTS850 to a network as shown in Figure 3–2.