26
G.703 CODIRECTIONAL CONVERTER
3.5.3 DTE C
ONNECTION
The DB25 female DTE connector provides an interface for input/ output
data, as well as clock and control signals, between the Converter and a DTE.
(The cables and pinning required for different types of DTE connections are
shown in the
Appendix
.) To make this connection, run an appropriate cable
from the DTE to the Converter and attach the cable’s DB25 male connector
to the Converter’s DTE connector.
3.5.4 A
SYNC
S
ECONDARY
-C
HANNEL
C
ONNECTION
To enable an async secondary channel, you must use a special T-cable which
connects both the primary and secondary channels to the Converter through
the Converter’s DTE connector. Refer to Figures A-3, A-7, and A-11 in the
Appendix
.
NOTE
You can use an async secondary channel only when you run a primary
channel at 56 or 48 Kbps on a clear channel, and you must have a G.703
Codirectional Converter at both ends of the link.
The rules for operation with an asynchronous sub-channel are:
• A split (dual) cable should be purchased or prepared. Refer to Figures
A-3, A-7, and A-11 in the
Appendix
.
• Signal Ground and Protective Ground are used for the high-speed sync
channel as well as for the async channel.
• Pin 8 and Pin 4 can be used to carry only receive and transmit data for
the async channel. They cannot be used to carry control signals for the
high-speed sync channel.
