Tektronix OI1125, Instruction Manual, Page: 64 / 88

Performance Verification
52
OI1125 E/O Transmitter Instruction Manual
Oscilloscope Setup.
Set the TDS8000 Vertical settings as follows:
NOTE
. Due to differences in oscilloscope firmware, your setup steps may differ
slightly.
1. From the toolbar, select Setup
→
Vertical.
2. Click the Optical>> button.
3. Set the Signal Conditioning mode:
a. In the Wavelength field, select 1550 from the drop-down menu.
b. In the Filter field, select OC-48 from the drop-down menu.
NOTE
. You must change the Filter field setting when you take measurements at
other data rates. See Table 15.
A filter is not used for the 12.50 Gb/s data rate. Instead, set the Filter field to
None, and set the bandwidth to 12.50 GHz.
Table 15: Signal conditioning mode settings
Data rate,
Gb/s Wavelength
field setting Filter field
setting Bandwidth
setting, GHz
2.488320 1550 OC-48 –––––––
9.953280 1550 OC-192 –––––––
12.500000 1550 None 12.50
4. Select the Trig tab to set the trigger parameters.
a. In the Trigger Source box, select External Direct.
Preview the Eye Pattern.
1. Turn on the BERT data and clock outputs.
2. Enable the tunable laser.
3. Enable the transmitter.
4. Turn on the channel that the optical module is plugged into.
5. Press Autoset.
The oscilloscope displays an eye pattern as shown in Figure 19 on page 54.