CTI Products MCN RCD System Planner - Manual (Page 7)

Section 2. System Operation
MCN Comparator Display System Planner Page 3
2. System Operation
This section describes the basic operation of both Comparator I/O Modules and User Interface
Modules in a comparator display system. Two systems are described:
•
A PC based system connected to three DIGITAC, Spectra-TAC, or Ericsson / GE comparators,
and
•
A console-based system connected to an ASTRO-TAC comparator.
In an MCN system, the Comparator I/O Module accepts VOTE, RECEIVE, DISABLE, and FAIL
receiver status messages from the comparator and sends them to a User Interface Module over the
MCN network. User Interface Modules then display the comparator status information on a console or
PC.
Likewise, when a User Interface Module sends FORCE VOTE or DISABLE commands, the
Comparator I/O Module translates the commands and sends them to the comparator.
2.1 PC-Based System for Digitac, Spectra-TAC, or Ericsson
Comparators / Voters
2.1.1 System Description
Figure 2 shows a small system made up of three Comparator I/O Modules (the CIBs) and one User
Interface Module (the HIB). The PC can monitor and control all three comparators from a single
screen. When a receiver is force voted from the PC, a FORCE VOTE message is generated by the
MCN RCD software and sent to the CIB that is controlling that particular receiver. When the CIB
receives the FORCE VOTE message, it will drive the receiver’s VOTE output line to signal the
comparator that the receiver is being force voted. A similar process occurs when a receiver is disabled
from the PC.
Going the other direction, when the comparator detects that a receiver is active, it will drive the RX
input of the CIB. The CIB will then generate a RECEIVE message and send it to the HIB so that the
active receiver can be shown on the PC screen. A similar process occurs when the comparator
generates a Vote (driving the CIB’s VOTE input) or a Fail (driving the CIB’s FAIL input) signal.
COM 2
COM 1
CA-80041-100
2
COMPARATORS
CIB
CIB
CIB
T
HIB
T
1
3
P/S
OUT
IN
IN
IN
IN
OUT
OUT
OUT
P/S
LOCAL PC
Figure 2 - System Operation Example
(P/S = Power Supply, T = Network Terminator)