status information provided is Alarm/No Alarm; Access/Secure; AC Power/AC Power Fail (Battery Power). Refer to J-
SIIDS TM 5-6350-264-14-1 for additional information.
1.13.2 Uninterruptible Power Supply (UPS) Functional Description. The UPS is an on-line uninterruptible power
system. It provides continuous power to the CMA and computer. In the event there is a loss of facility power, it also
provides at least 4 hours of backup ac power before recharging of its batteries is necessary. There is an interface
between the CMA and the UPS for the purpose of monitoring the ac power status. When a loss of ac power occurs, the
power loss is detected and battery operation is indicated at the monitor.
1.13.3 Converter Multiplexer Assembly (CMA) Functional Description. The CMA (figure 1-5) receives the FSK
signals from the J-SIIDS data transmitters located at up to 64 remote areas. It also receives the power status from the
UPS. The FSK signals are processed by the CMA for transmission to the computer.
Data signals from the J-SIIDS data transmitters are input at the terminals marked Area 1 through 64 on the inside of the
rear door of the CMA. The data signals are input on four surge suppressor CCAs that can accept 16 inputs each. Input
line pairs are connected to the terminals labeled A and B for each remote area. The output of the surge suppressor CCAs
are routed through wiring harnesses to the two drawer assemblies. Each drawer assembly has a right and left backplane
and 16 remote area inputs are routed to each backplane. Each backplane is divided into two modules. Table 1-3
provides the module relationships to the remote area inputs.
Each module consists of eight Data Receivers and one CPU (figure 1-6). The FSK signals are applied to the Data
Receiver CCAs where the signals are demodulated. The demodulated signals are applied to the CPU, where the
encoded data from each data receiver output are collected and formatted for transmission to the Communications CCA
located in the computer.
Table 1-3. AMG Modules.
Backplanes From Front View
Each CPU also adds the condition of the UPS power and the CMA tamper switches to the formatted data. Each CPU
CCA, which has a unique address, outputs its data to the Communications CCA when it is polled by the computer. Each
CPU is polled once per second.
1.13.4 Communications Circuit Card Assembly (CCA). The Communications CCA is a dual channel RS-485
asynchronous serial communications adapter for computers implementing an ISA compatible input/output (I/O) bus. It is
installed in the computer and provides the interface between the computer and the CPUs within the CMA. The
Communications CCA provides for full duplex operation. The data transfer rate between the Communications CCA and
the CPUs is 9600 baud.