General DataComm Xedge 6000 Series Hardware Installation page 151

Network Timing Modules
Jumper Settings
The X1 Input Impedance jumper allows you to select the input impedance for the RC IN connector
signals: 75 ohms or 120 ohms.
The X2 Chassis Ground jumper allows you to select balanced (BAL) or unbalanced (UNBAL) for
the RC IN connector signals. As shown in
chassis ground. With Balanced mode, pin 3 is isolated from chassis ground.
Figure 6-4
Cabling
The NTM-E1 can use a 120 ohm shielded twisted pair cable, following
insertion loss is 6 db at 2048 kHz. The cable terminates with male DB15 connectors. With this
cable, the Input Impedance jumper must be set to 120.
The NTM-E1 can also use a 75 ohm coaxial cable, following
is 6 db at 2048 kHz. With this cable, a DB15 to BNC adaptor is required, and the Input Impedance
jumper must be set to 75.
Table 6-2 E1 Node Timing Module
Connector
Received Clock Input
(RC IN)
Note
IMPORTANT! In some installations with specific RF/EMI problems, it may be desirable to use the Input
Impedance jumper to disconnect the shield-to-chassis ground connection for the RC IN link.
032R440-000
Issue 17
NTM-E1 Jumper Positions
Signal Name
Receive Return
Chassis Ground
Receive Signal
Chassis Ground
Xedge 6000 Hardware
Installation & Setup Guide
E1-Node Timing Module (NTM-E1)
Table 6-2, with Unbalanced mode, pin 3 connects to
X1
75 120
X2
UNBAL BAL
law. The maximum insertion loss
F
Pin Number
(Balanced Mode)
3
- -
11
shield
law. The maximum
F
Pin Number
(Unbalanced Mode)
- -
3
11
shield
6-5