NRTB

  • AKKR-1M
  • Integral 400 wireless modem
  • Linear antenna array

Integral 400 wireless modem

Integral 400 wireless modem is designed for transmitting digital data through a radio channel. The access time to the radio channel of the embedded specialized transceiver is small (7 ms) which allows creating radio systems with the minimum information delivery time being their important criterium. The modem ensures an asynchronous data exchange on the air at speeds of 19200 bps or 9600 bps in the channels with frequency spacing equal to 12.5 KHz. It supports main industrial protocols.

The embedded diagnostics application is available on a real time basis to allow an absolute control of the wireless modem state (power supply voltage, temperature, receive level, power output, standing-wave ratio, data transmission accuracy). Operating the modem and obtaining diagnostics information is done with the aid of an additional SETUP port - a user-friendly graphics program running under any operation system supplied. The program allows for circular questioning of all the network’s available Integral 400 modems, for displaying of the data obtained, and for cyclic storing of diagnostics information in the data base and updating the ROM of the modem program. The program allows for a complete remote and local configuration and operation of wireless modems, display and storage of radio network traffic with time parameters of sent packages accurate to milliseconds and for reception of information on cross receive levels between all stations in the network. 

The wireless modem supports operation with control through RTS and in DOX mode (data-activated transmit), which does not require an RTS signal to control the stream, i.e. the transmission is initialized by the data received by the wireless modem port. There is a big built-in transmit-data buffer (from 14 to 32 Kb) and if a data stream from terminal station is significantly greater than the transmission speed through a radio channel the control is done by CTS signal.

The wireless modem is ideal for building big radio networks as it has a built-in network time-division controller. The wireless modem can be used in many point-to-point and multi drop applications, there can be up to 4094 wireless modems within one radio network. There is a possibility to route packages within a single-frequency network and between multiple-frequency networks which is vital when building long-distance networks. Support is also given to address data transmission.

To reduce the impact of random impulse interference there is a possibility to apply noiseless coding with dynamic interleaving. The modem encodes and dynamically interleaves information depending on the size of the data transmitted but it does not augment the block up to the required size which is usual for most standard coders. When this happens coding losses are minimum and they do not change depending on the size of transmitted blocks, they amount to 10 percent of transmission speed.

The wireless modem has an embedded evaluation function to check correctness of transmitted data. The CRC-32 standard cyclic redundancy code is used for this purpose.

The wireless modem’s receive path has increased overload capacity which ensures stable transmission of data at close ranges.

Wider variants of delivery are possible:

  • Integral 400М model is engineered for use in severe environmental conditions with the operation temperature ranging from –40 °С to +70 °С. It is encased in dust/moisture-proof housing. It withstands sinusoidal vibration and multiple mechanical shocks.
  • Integral 400МR, 400SR model is used as a standard voice radio station with all main functions available. With this end in view, an external push-to-talk switch and a loudspeaker is connected to the modem.
  • The basic software enables displaying the state of all network’s available Integral 400 wireless modems, using circular questions about the condition of wireless modems. It also allows for total remote configuration and control of all wireless modems, database management and periodic preservation of the database relating to the condition of all wireless modems and radio communication traffic.

General characteristics

Operating frequency range from 410 up to 480 MHz
Number of subbands of operating frequency ranges 13
Number of channels in the range 800
Operating temperature range from –25 °С up to +60 °С
Power supply voltage from 10 up to 40 В
Antenna connector BNC socket
Overall dimensions 16(L) x 14(W) x 4(H) cm

Receiver

Frequency spacing 12.5 KHz
Receiver sensitivity < 0.3 mkV (signal/noise 12 dB)
Input signal peak level 10 мВ
Selectivity (25 KHz) at least 70 dB
Intermodulation at least 70 dB

Transmitter

Output signal modulation type GMSK (BT= 0.3 or 0.5)
Transmitter frequency stability 2.5 ppm
Power output at least 5 W
Output power control from 0.01 up to 5 W, discreteness - 1024 discrete steps
Transmitter attack-time < 7 ms
Transmission band without adjustment 10 MHz
Transmitter runtime indefinite time

Modem

Speed of information exchange on the air 9600 or 19200 bps
Terminal station connection interface RS-232C
Data exchange speed with the terminal station 9600-115200 bps
Data format 5, 6, 7, 8 bits; no, even, odd parity; 1 or 2 stop bits
Size of data buffer for transmission From 14 up to 32 Kb
Communication control RTS-CTS, DOX, mixed

Built-in network interface controller

Principle of operation of the network interface controller time division
Minimum time window 3 ms
Number of stations in the network up to 4094
Number of subnets up to 16

  • We offer a completely domestic technology developed jointly by NIRIT and NRTB companies. It is second to none of any known foreign analogues in terms of radio channel parameters. An embedded controller allows setting up a radio network of any complexity at short notice.
  • If you buy wireless modems from our company you will be offered comprehensive aid not only in creating data radio communications system but in getting radio frequency licenses and in certifying the system by appropriate agencies.
  • Our software, capable of demonstrating the network functioning in its entirety, can be used for optimal configuring of industrial controllers at sites for the radio channel at the earliest possible date.
  • A remote control of all wireless modems will save your time at the initial stage of configuring a network and during its operation.
  • With the maximum transmission speed of 19200 bps and BT = 0.3 GOST 12252-86 requirements for spurious emission in the adjacent channel with the frequency band of 25 KHz are satisfied.
  • A ramp-up time to the operating mode of standard transmitters may amount to 500 ms. It takes less than 7 ms to start operating in our transmitter’s mode, which makes it possible to begin actual transmission of information in 40 ms with due consideration of synchronization and service information.
  • To meet your requirements to conditions of operation and to data transmission there is a possibility to expeditiously change both software and hardware representation of the wireless modem.
  • The Integral 400 wireless modem owing to the built-in network interface controller and a set of hardware and software functions, such as, checking correctness of the transmitted data with the aid of CRC-32, antinoise coding, continuous data transmission, defining the size of transmitted packets, a large built-in buffer, address transmission, etc., enables reservation in wireline networks through a radio channel, without having to change a data gathering and control algorithm.

Industrial process control networks, automotive transport operational-dispatching and monitoring systems were debeloped on the basis of wireless modems. They continue to operate to the best advantage.