Textron Greenlee Communications DataScout 10G, User Manual

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Users Manual
DataScout 10G & 10Gx
85
DDS and DataCom
The DDS 4-Wire interface uses an RJ48 jack with a pin-out of pins 1&2 transmit (out-
put) and pins 7&8 receive (input). The test set emulates a CSU/DSU and responds to
the following loopback commands:
►
Latching CSU, CCITT
►
Latching V.54
►
Alternating CSU
►
Alternating DSU
The DDS interface is 135 Ohm and supports TERM and THRU modes for both primary
and secondary channels. Primary channel are unframed and use bipolar violations to
transmit control codes such as:
►
CMI (Control Mode Idle)
►
DMI (Data Mode Idle)
►
Loopbacks.
The test set encodes and decodes all DDS control codes in Primary and Secondary
channels. 64K Clear channel has a line rate of 72K but a data rate of 64K due to the
frame format of 64Kbps.
For monitor testing please use monitor adaptor. With this adaptor your local loop can-
not be greater than -10dB as the adaptor adds loss to the monitor circuit. This is
adapter provides features most DDS test sets do not have and allows you to monitor
DDS circuits as you would a T1 circuit.
DDS 4-Wire Connections
Connect the 4-Wire local loop RJ48 male with a pin-out of pins 1&2 transmit (output)
and pins 7&8 (receive) to the test set. If the test set immediately detects a CSU loop-
back the pairs are reversed (1&2 and 7&8 are swapped). After connection, LOS alarm
will disappear and the
“
misc. status messages
” line will display the received signal
level and sealing current (voltage across RX & TX pairs).
You may want to perform a cable loss measurement of the receive and transmit pair at
the Nyquist frequency (1/2 the line rate), for example at 56K the Nyquist is 28K Hz
(greater than -48dB line loss or greater than -40 dB at subrate Nyquist). To transmit
and receive frequency use the TIMS application and follow the procedure in the TIMS
section of this user manual or simply configure TIMS for freq & level measurements at
135 Ohm impedance.