Telos Zephyr Xstream - Manual (Page 166)

USER’S MANUAL
Section 9: The V.35/X.21 Interface Option 154
6. Once the connectors are aligned, push the V.35/X.21 option card straight
down into the connector on the motherboard. Only moderate pressure
should be required to seat the card.
7. Fasten the option card to the rear panel of the chassis using the two 4‐40
button head screws previously removed in step 3, above.
8. Replace the lid. If you have a Zephyr Xstream MXP, align the blue bumpers
with their corresponding holes.
9. Fasten the lid using the 18 (or 14) screws removed in step 1.
10. To use your V.35/X.21 interface you will need to connect an appropriate
cable:
• For V.35 use Telos part # 2091‐00023 (old #9812‐0000)
• For X.21 use Telos part # 2091‐00024 (old #9822‐0000)
11. To enable the X.21 Interface, change the Interface menu selection In the TEL
menu to V.35 Split or V.35 Single as appropriate for your application.
9.2 Uses for the X.21/V.35 Interface Option
SWITCHED 56
Switched 56 is a transition technology which is being offered primarily in the few areas of the
USA & Canada where ISDN is not available. As the name suggests, this is a service that permits a
single bi‐directional digital data stream to be sent at a 56kbps rate. A switched 56 line requires
a Channel Service Unit/Data Service Unit (CSU/DSU) to interface the digital line with the Zephyr.
V.35/ X.21
INTERFACE
(MINI-40 PIN)
Zep hyr™
Xstrea m
Line Port
Da ta Port
(V.35/ X.21)
CSU/ DSU
To SW56
PORT1
PORT2
(not used )
Typical setup for mono configuration. Only one port is used.
Switched 56 comes in two varieties: two‐wire and four‐wire. The one you need depends upon
the service style offered by your telephone company. In many cases, you can purchase this
equipment from your Telos Systems dealer. The most popular manufacturer for these Switched
56 CSU/DSUs seems to be: