Terminal Resistors; Figure 3-6 Jp5 Jumper Location; Figure 3-7 Location Of Jat1, Jat2, Jan1 And Jan2 Jumpers - Topex MobiLink ISDN2GSM User Manual

TOPEX MobiLink ISDN2GSM User`s Manual
Location

Figure 3-6 JP5 jumper location

Jumper JP5 is located near the top left corner of the printed circuit
board of MobiLink. Immediately to the right of JP5 you can see the
connector for the external antenna. JP5 is alone (no other jumpers in
the near) and it is in vertical position.
3.8.

Terminal resistors

Use
These pairs of jumpers (JAN1 and JAN2 for the NT interface, JAT1
and JAT2 for the TE interface) configure the impedance matching
(termination) resistors for the respective interfaces.
By default, these jumpers are ON so the terminal resistors are
connected. You should take the jumpers OFF if terminal resistors are
not required.
When you have several ISDN devices connected to an ISDN line, the
line must end with impedance matching resistors, also called terminal
resistors. This is required, for instance, when cascading several
MobiLink interfaces and using synchronization.
One solution for termination is to use a terminal block with matching
resistors inside. But if the last device is a MobiLink equipment, you
can use the termination resistors that are included with the equipment.
Remember, out of several MobiLink units cascaded on the ISDN line,
only the last unit must have the termination resistors enabled.
Location

Figure 3-7 Location of JAT1, JAT2, JAN1 and JAN2 jumpers

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