SFCD: Federal Commander Digital System - Federal Signal

RTU Description
Federal Commander Digital System
For purposes of this manual, an RTU (Remote Terminal Unit) consists of the siren control unit,
usually a Federal Signal model FCT, MCPT, Ultra Voice, or UVIC series controller.
The RTU is a completely self contained single board microprocessor based monitoring and
control unit. It has the capacity to store siren activation functions uploaded from the CCU or
SS2000D. It also collects siren status and diagnostic information for report back to the CCU. All
programmable parameters are stored in non-volatile memory and are not dependent on battery
backup.
Each RTU can communicate status and alarm data to one or more CCUs or other RTUs over a
radio link, or dedicated telephone lines, depending on the individual system ordered. All data are
transmitted in a digital format as a stream of characters, serially organized and transmitted at a
rate of 1200 bits per second.
In the system network, the RTU and the radio modem (SS2000D or MODEM-MSK) work as a
complex data communication pair. Data protection techniques and handshaking is included so
that messages do not get corrupted and are received correctly.
If an alarm condition is reported by the RTU, the CCU can be programmed to initiate an alarm
and place a series of telephone calls until it reaches and reports to key support personnel. Status
alarms from any RTU are handled the same way so that maintenance action can be taken at
once. This means that alarms can be set up to trigger as they happen enabling action to be taken
before extensive downtime occurs.
Any RTU in the system may act as a communication repeater, allowing wide area coverage
capabilities without the necessity of expensive high power transmitters or large antenna arrays.
The Commander System RTUs are designed with reliability as a number one priority. In the
unlikely event an RTU fails, the entire control board in the RTU assembly may be switched out by
non-technical personnel in less than 5 minutes with only a standard screwdriver.
Further details of the RTU are included in user manual for the type of RTUs included with your
system.
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Introduction