Installation manual

LBI-38988
8
LBI-38430 - MASTR IIe Control Shelf Maintenance
Manual.
LBI-38636 - MASTR III Base Station Installation
Manual.
LBI-38812 - EDACS Interface Panel Maintenance
Manual.
LBI-38822 - Turbo Board (GETC-1e) Maintenance
Manual.
LBI-38894 - GETC Trunking Card Maintenance Manual.
LBI-38896 - EDACS Site Downlink and CEC/IMC
Uplink Configuration Manual.
LBI-38985 - EDACS Site Controller Maintenance
Manual.
SRN-1010 - Software Release Notes for GETC Turbo
Board Software, 344A4414G1 only.
SRN-1024 - Software Release Notes for GETC 900
MHz Software, 19A705595G8.
SRN-1060 - Software Release Notes for GETC-1e
Software, 349A9607G1 (or later).
SRN-1062 - Software Release Notes for Turbo Board
with GETC-1e Software, 344A4414G2 (or
later).
TQ-3357 - GETC Shelf Programming Manual
DESCRIPTION
The Station GETC is the foundation of all EDACS
trunking operations. It is capable of operating in the
Trunked Failsoft mode or as part of a fully trunked system
or network. In the Trunked Failsoft mode, one of the
Station GETCs operates as the Control Channel GETC,
providing the command and control link between the mobile
radios and the EDACS system. The remaining station
GETCs operate as Working Channel GETCs and enable or
disable selected repeater channels for the actual voice or
digital data communication. Each of the Station GETCs has
the ability to function as a Control Channel in the event the
current Control Channel GETC fails.
In a Fully Trunked EDACS network or system (Figure
1), the Station GETC's function as either Control Channel or
Working Channel GETCs. In this environment, the Site
Controller Computer directs all communications, and
designates the Control Channel and Working Channel
GETC's. This allows EDACS to provide advanced features
such as Dynamic Transmission/Message Trunking, Local
Telephone Interconnect, Activity Logs, and Management
functions.
However, should the Site Controller fail, the EDACS
system defaults to the Trunked Failsoft mode. In this mode,
one of the GETC's assumes the role of Control Channel
GETC and directs Working Channel assignments using the
Backup Serial Link (BSL). Should the Control Channel
GETC fail, one of the other Working Channel GETC’s
assumes the Control Channel function. The end result is
reliable, high performance trunked communication.
The Site Downlink GETC provides the communication
path between the site and the Integrated Multisite and
Console Controller (IMC) or the Console Electronics
Controller (CEC).
OPERATION
The Station GETC’s communicate with the Site
Controller through an RS-232C port (J100), see the
Interconnect Diagrams, operating at 19.2K baud. Additional
communications parameters are one start bit, eight data bits,
and one stop bit.
The designated Control Channel GETC communicates
with the Working Channel GETC's using a Sync line that
indicates outbound Control Channel data and inbound
mobile data. The Sync line is connected in a bus fashion to
each Station GETC.
CONTROL CHANNEL
The Control Channel GETC continuously provides
outbound Control Channel data. The data stream consists of
message frames containing information such as Channel
Assignments. The Channel Assignment message includes
the originating mobile's LID, communication type, Trunking
mode, communications channel, and the group or individual
involved in the call.
The mobile radios synchronize their transmissions on
the Control Channel to reduce Control Channel collisions.
The designated Control Channel GETC processes the
inbound data prior to passing the data along to the Site
Controller. When operating in the Failsoft mode, the
Control Channel GETC also produces the required Channel
Assignments.
Control Channel Jamming
Whenever an invalid signal is present on the inbound
Control Channel for longer than six seconds, the Control
Channel GETC generates a jamming alarm . The Station
sends the alarm to the Site Controller which can initiate