Tektronix 071-0855-05 user manual Signal Structure, Test Pattern

Operating Basics: User Interface

BERT Mode

For some modules there is a third option available from the Signal Standard menu, the BERT mode. With this mode, the OTS9100 becomes a BERT generator. The Test Pattern selection for the active channel is the only valid selection on the transmitter signal setup page when BERT mode is selected. When the signal standard is returned to either SONET or SDH mode, the settings will return to the current selections in the setup menus.

Most LED indicators are also invalidated by the BERT mode. The only valid LEDs are Signal Present, TSE, and LSS.

Signal Structure

Signal structure allows the user to choose the mapping structure of the received signal. The mapping structures provided are listed in the table below. As shown, the structures all provide concatenated structures.

SONET	SDH
1 x STS-192c	1 x VC4-64c
4 x STS-48c	2 x VC4-16c
16 x STS-12c	16 x VC4-4c
64 x STS-3c	64 x VC4
192 x STS-1	192 x VC3

Active Channel(s)

The Active Channel(s) section controls the settings for signal structure and test pattern of the selected active channel(s). To set the active channel, use the up/down cursors or click the Set Channel button. When the Set Channel button is clicked, the bar for Active channel changes into an interactive menu. Type in the text box to select the channel or click Set Channel 1 to choose channel 1.

Test Pattern

Test Pattern allows the user the select a pattern to fill the chosen active channel of the internally generated 9.95238 Gb/s signal. The patterns available are:

PN15 (PRBS 2^15-1), Inverted PN15 (ITU O.151)

PN23 (PRBS 2^23-1), Inverted PN23 (ITU O.151)

PN31 (PRBS 2^31-1), Inverted PN31 (ITU O.150) All Zeros

All Ones

Fixed Data (8-bit)

In order to use the POS testing capabilities, POS must be selected as the Active Channel Test Pattern. In addition, POS must be selected as the Active Channel Test Pattern in the Receiver Setup menu.

NOTE: To receive a POS test pattern, the Signal Structure must be set to STS-192c.

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