SITE SECTIONS

SFU

Remote control system


Remote control system is designed to transfer electronic guidance commands from base station (control center) to object station’s operation unit and to accept response information about the condition and operation of control objects’ sensors. Remote control system (SDU) includes the base station (BS), the object station (OS) and the retranslator (RT). BS is used to transfer control commands over the radio channel from the control center to the object and to accept information about the object’s condition. OS accepts control commands over the radio channel from BS, outputs commands to the object, accepts the information about object’s condition and transfers this data to BS. RT provides BS communication with OS for long distances or when it’s cross country locality. When using RT, SDU effective range is no less than 35 km (when visual range is between RT – BS and RT - OS). Under the conditions of direct visibility, when the distances are no more than 25 km between BS and OS, it is possible not to use retranslator. The user interface and equipment of BS and OS allow to set SDU against direct mode communication (point-to-point) or through RT.

Remote control system structure

SDU

Structurally BS, OS and RT equipment is located in the metal hermetic boxes.

SDU

BS equipment includes:
- laptop computer (PC) of the type "Samsung" Pentium 4M notebook with RS-232 port;
- adapter (modem) of record V23 to provide PC communication with a radio station;
- radio station Motorola CM-140;
- antenna BF-2М2 with 50 m radio-frequency cable RG-213;
- radio station power supply 12 V., 10 A.
OS includes:
- based on microprocessor AVR Atmega128 controller;
- adapter (modem) of record V23 to provide controller’s communication with radio station;
- radio station Motorola CM-140;
- antenna BF-2М2 with radio-frequency cable RG-213 with the length up to 40 m;
- operation unit (OU) with local input-output interface for interaction between inputs (loads), outputs (sensors) and plug-in object;
- test unit for validity check of interaction between OU and control object inputs and outputs without object’s installation;
- accumulator battery NBGF Delta DT1226 , + 12 V., 26 A*hr.
OS Connectors for plugging of outer loads (3 connectors), accumulator storage battery and antenna radio-frequency cable are located on the body side panel. RT differs from OS in the absence of operation unit, test unit and connectors for plugging of outer loads. SDU radio commands are transferred in the form of messages, which include header, talker and listener addresses, control command’s code and characteristics, check sum. Included in BS, OS and RT radio stations with capacity 28 Wt operate at a frequency of 174,000 Mhz. Interaction between rf modem and OS and RT controllers and BS PC is performed on bit-serial interface RS-232 with hardware control of the data flow on RTS line. Operating mode – Half Duplex, rate of exchange – 1200 bps, odd-even check, 8 b of data, 1 stop bit. BS software (SW) implemented in PC allows remote control system operator to send the commands of object’s control to OS, to prompt for OS and RT condition, to make parameter settings and operation modes of SDU. RCS SW provides remote voltage measuring of accumulator OS and RT batteries and remote switching off of OS and RT under the BS operator’s command. Remote control system has some levels of protection against unauthorized remote command start: switching on BS PC after password entry, BS program start using passwords with 2 access levels, instruction coding and decoding of BS and OS control commands, integrity check of transmitted on the radio channel to RT and OS messages with the help of redundant check codes.

Main technical characteristics
- continuous work time of the system, hrs: no less than 3;
- the time of commands’ transmission from BS to control object, no more than, s:1.
OS operation unit:
Outputs: 5 opto-isolated outputs;
Load resistance, Ohm: no less than 8;
Output amplitude, V.: from 27 to 30;
Outputs - 7 opto-isolated outputs.
Motorola CM-140 radio station:
Carrier frequence, mhz: 174;
Sending set capacity, Wt: 28;
Frequency stability, %: 0,00025;
Current absorbed during sleep condition mode, A: no more than 0,3;
Adapter (rf modem) of record V23:
Operation mode - Half Duplex;
Interchange format on interface RS-232 - 1200, E, 8, 1.