Tektronix 071-0855-05 user manual Through Mode Overwrite menu

Operating Basics: User Interface

Through Mode

When using through mode, a number of the overhead bytes may be overwritten as the external signal passes through the card. This is done through the use of the Through Mode selections available in the Overhead menu, as shown in Figure 2-13. If the box is checked for Regenerate B1/B2 Parity, the receiver will recalculate the B1/B2 parity and insert the new information into the overhead as the signal is passed through the card. To disable B1/B2 parity regeneration, ensure that the Regenerate B1/B2 Parity box is not selected.

Figure 2-13: Through Mode Overwrite menu

To overwrite an incoming byte, click in the box beside the selection under the Overwrite Incoming heading. If you wish to keep a byte from being overwritten, make sure the box beside the selection is not selected. The bytes available to be overwritten are J0 Trace/C1 Byte, E1, F1, D1..D3 Section DCC, K1..K2 APS, D2..D12 Line DCC, S1 Sync Status, M1, Z2, and E2. Parity regeneration is always enabled if the user chooses to overwrite any incoming Overhead bytes.

NOTE: There is no explicit byte edit for M1. Checking the M1 overwrite setting provides the ability to insert REI-L.

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