ComBlock COM-1826 Руководство - Страница 13
Просмотреть онлайн или скачать pdf Руководство для Модем ComBlock COM-1826. ComBlock COM-1826 19 страниц. Tdrss spread-spectrum modem
Печатать страницуDigital Test Points
The digital test points below are only available
when no ADCs/DACs are installed.
Test PointDefinition
A1
UDP/TCP input data activity.
SDDS receive data valid flag from UDP or TCP.
(8ns per input byte)
A2
SDDS input buffer underflow condition. '1'
when the sender is not fast enough.
A3
Recovered carrier/center frequency (coarse)
A4
Carrier lock
A5
Code lock
A6
Signal present
A7
Recovered chip clock
A8
Recovered I-channel symbol clock
A9
I-code start
A10
I-code replica
A11
I-channel before despreading (compare with
code replica)
A12
Demodulated bit (I)
A13
Demodulated bit (Q)
A14
BER tester synchronized (I or Q depending on
REG27(3))
A15
Byte error detected by BER tester (I
or Q depending on REG27(3))
A16
Viterbi decoder (I) synchronized (pulse every 1K
bits)
A17
Viterbi decoder (Q) synchronized (pulse every
1K bits)
A19
Periodic pulses every 2047 bits when receiving a
PRBS-11 test sequence
Operation
Monitoring & Control
M&C is possible over USB and LAN/TCP.
A pre-requisite for using USB is the prior
installation of the ComBlock USB driver.
Monitoring and control is through the USB and
LAN xA connectors on the back panel.
At manufacturing, the default M&C LAN address is
172.16.1.2. It can be subsequently changed via USB
or LAN/TCP.
The LAN xA connector is also shared with TCP
connections for modulator inputs and dynamic
profiles inputs.
SDDS input stream
The LAN xB connectors on the back panel are
reserved for SDDS-formatted input streams.
The input stream can be received on UDP port
29495 or TCP-IP port 1028. Control register
REG0(0) selects UDP versus TCP.
The static IP address is defined in control registers
REG37-40.
Note: It is important to ensure that the data source is
fast enough to send 200 Mbits/s of UDP or TCP
data with latency less than 2.5ms (the receiver input
elastic buffer depth). When in doubt, please check
the test point A2 with an oscilloscope.
13