Specifications
SCOPE
The Conventional Network Interface (CNI) provides the
communication link between a conventional repeater
(MASTR II, IIe, or III) and an Enhanced Digital Access
Communication System (EDACS). This communication
link is provided by modifying the Ericsson GE Trunking
Card (GETC) which interfaces with the Console Electronics
Controller (CEC) or Integrated Multisite and Console
(IMC) Controller. This manual explains the CNI operation
and the steps necessary to reconfigure and program the
GETC for CNI operation.
INTRODUCTION
The CNI station equipment is part of a wide area net-
work that is interfaced to a CEC/IMC through an Uplink
configured GETC. Figure 1 shows the CNI and Uplink
connection which is implemented using a four-wire, data
grade, type 3002 audio (telephone) line. The audio connec-
tion between the CEC/IMC and the repeater is also a four-
wire audio (telephone) line.
The CNI GETC converts analog Channel Guard tones
into EDACS Group ID’s (GID) based on mapping informa-
SPECIFICATIONS*
Input Voltage +13.8 Vdc •20%
Current Drain with 9600 Baud Modem 1.5 Amp (typ), 2.0 Amp (max.)
Operating Temperature -22°F to +140°F
(-30°C to +60°C)
Dimensions (H x W) 1.75 x 19 inches (EIA rack mount)
(4.5 x 48.3 cm)
Repeater Compatibility MASTR II or IIe, all frequency bands
MASTR III, all frequency bands
Network Interface: 2 & 4 wire circuits
(audio and data) Bell Std 3002 grade
Data Rate 9600 Baud
Transmit Level 0.77 Volts rms (0 dBm)
Receive Level 0.16 Volts rms on J3A-32 of GETC Logic Board
Repeater Audio
Transmit Level 0 dBm, 0 Vdc offset
Receive Level 0 dBm, 0 Vdc offset
Channel Access 500 to 750 ms (IMC site)
Valid Channel Guard Tones (Hz) 67.0, 71.9, 74.4, 77.0, 79.7,
82.5, 85.4, 88.5, 91.5, 94.8,
100.0, 103.5, 107.2, 110.9, 114.8,
118.8, 123.0, 127.3, 131.8, 136.5,
141.3, 146.2, 151.4, 156.7, 162.2,
167.9, 173.8, 179.9, 186.2, 192.8
CNI Group/Channel Guard Pair 4
* These specifications are intended primarily for the use of the service technician. Refer to the appropriate
Specification Sheet for the complete specifications.
LBI-38986
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