DM16E1 / DM4E1 Operation and Installation Manual - 204-4001-19
86
10.
STRAPS
10.1. Connecting the Frame Ground to the Signal Ground
Strap E1, located at the power unit, allows the frame ground (ground pin of the power connector) to be
connected to the signal ground of the card. To access this pin, it is necessary to remove the unit through
the front panel. This is the only strap available at the power unit.
Position 0-1: frame ground and signal ground separated
Position 0-2: frame ground and signal ground connected
10.2. E1 Tributary Channel Straps
In the straps located on the equipment rear panel, it is possible to configure which of the E1 channels are
connected to the frame ground of the equipment (position Connected or C) and which are isolated
(position Isolated or I).
These configurations may be performed separately.
10.3. External Clock Strap
This strap is located on the equipment rear panel. Its configuration indicates whether a charge of 75
Ω
will
be inserted or not in the external clock input.
When set to ON, the external clock input presents an impedance of 75
Ω
. When set to OFF, the input
impedance is high, allowing for the connection of a clock source to several devices simultaneously.
For further information, see item 12.3.
10.4. V.35 and V.36/V.11 Interface Selection Straps
Straps E16 to E24 should be set to position 0-2 in order to enable the use of digital interface with V.35
DTEs. On the other hand, they should be set to 0-1 in order to enable the use of V.36/V.11 interface.
Factory configuration is 0-2.
These straps are located on the main card, below the aggregate cards. They should be removed in order
to be accessed.
For further information, see item 5.
If any of the units is grounded, then the frame ground will be connected to the DM16E1/DM4E1 signal
ground.
When 120-ohm connections are used with RJ45 connectors, the straps should remain set to I. To obtain
further information, please refer to chapter 4.
