HP 37718A Installation And Verification Manual page 43

General Information
Specifications
VT-1.5 path overhead: All bytes except
V1, V2, V5 can be changed from the
default state using OVERHEAD
SETUP.
Default values:
V1,V2 - V2 and the 2 least significant
bits of V1 indicate the offset from the
pointer to the first byte of the VT
payload. The SS bits are 11. The
pointer offset value is determined by
the last setting of New Pointer test
feature.
V5 - Bits 1 and 2 are the BIP-2 parity of
the previous VT including V5 but
excluding V1 - V4 (unless V3 contains
a stuff byte). Bits 5 - 7 are set to 001
(Equipped). All other bits are set to 0.
J2 - 16 ASCII Null characters.
Z6 is transmitted as all zeros.
Z7 - is transmitted as all zeros.
Overhead sequence generation:
A single or multi-byte overhead
channel is overwritten with a single or
repeated sequence of programmed
values. The sequence can contain up to
five different values each being
transmitted for up to 64,000 frames.
RSOH:
6-byte channel A1A2
3-byte channel D1 to D3
Single byte channels J0, Z0, E1, F1,
A1A2 boundary, Row2 Column2,
Row2 Col3, Row3 Col2, Row3 Col3.
MSOH:
9-byte channel D4 to D12
2-byte channel K1K2.
Single byte channels: S1, M1, M0†,
Z1†, Z2†, E2.
† Z1 and Z2 are not present, and M0
replaces M1, in STS-1 mode.
High order POH :
Single byte channels: J1, C2, G1, F2,
H4, Z3, Z4, N1.
Overhead BER test:
SOH: J0, Z0, E1, F1, D1, D2, D3.
LOH: K1, K2, D4, D5, D6, D7, D8, D9,
D10, D11, D12, S1, M1, E2, M0.
POH: J1, C2, G1, F2, H4, Z3, Z4, N1
Any of the bytes listed above can be
selected and a BER measurement is
9
performed using a 2 -1 PRBS inserted
into a 64 kb/s channel. Single errors can
be added to the test pattern.
APS message generation:
Messages are displayed in text form as
per ITU-T G.783 for linear architecture
and to ITU-T G.841 for ring
architectures (MSP-ring). User
programmed sequences (K1K2).
DCC drop/insert: The data supplied to
the DCC port can be inserted into either
the section or line data communications
channel. Similarly, data can be dropped
from either channel. The data may be
dropped/inserted MSB or LSB first.
The data rate for access is: 192 kb/s
(SOH DCC), 576 kb/s (LOH DCC).
Optical interface stress test:
N bytes of the payload are overwritten
with a block of zeros or ones after
scrambling. N varies according to the
OC-n rate: OC-1 N=2 to 85.
OC-3 N=2 to 259.
OC-12 N=2 to 1042
OC-48 N=2 to 4174
Alternatively the ITU-T G.958 CID
(consecutive identical digits) test can be
selected.
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