RM4 HF Data Modem

RM4 HF Data Modem



RM4 HF Data Modem with 2G ALE for Naval and Military Communications

Suitable for long distance point-to-point data links, the RM4 provides high data rates and ALE controls for high frequency data communications for naval and military missions. Embedded in the RM4 unit, the 2nd Generation Automatic Link Establishment (2G ALE) Controller is activated with the appropriate AT Comms license key. 

Features

  • High Data Rate HF Modem and ALE controller in one unit
  • Up to 9600 bps in 3kHz
  • MIL-STD-188-141B App. A
  • MIL-STD-188-110 A/B
  • STANAG 4539 (QAM)
  • STANAG 4285 (PSK)
  • STANAG 4529 (NB PSK)
  • STANAG 4415 (ROBUS)
  • STANAG 4481 (P/FSK)
  • STANAG 5065 (MSK)
  • STANAG 5066 compliant interface (RC66 Combat Communications Suite)
  • Synchronous DTE port for high grade cryptographic equipment
  • Ethernet interface

Robust Waveforms 

Adaptive equalization mitigates the effects of HF channel multi-path. Convolutional encoding combined with soft-decision Viterbi decoding provides forward error correction. Cancellation of narrowband co-channel interference is accomplished via adaptive tone excision capable of eliminating up to four signals.
 
The RM4 offers customizable waveforms via a software pack option (see the reverse page for more details) 

Encryption for Security 

Encrypted data is routed through a crypto unit into the synchronous DTE port of the RM4. The modem Tx and Rx audio signals are fed to the HF radio. The radio is keyed by the RM4, while the unit monitors independent PTT activity on the radio. 

Remote Control 

The unit is fully controllable via RIPC/RAP1 remote control protocol (available from AT Comms). The unit supports split-site operation via two radio control ports.

Secure System Configuration with RM4 Unit

RM4 Unit front panel

Standard Coding
Modulation		 Data Rates & Characterestics Military Modem
Software Pack
M2 M3 M4
MIL-STD-188-110B
Appendix C		 C PSK/
QAM		 3200, 4800, 6400, 8000, 9600 bps ♦ - ♦
U 12800 bps ♦ - ♦
STANAG 4539 C PSK/
QAM		 75, 150, 300, 600, 1200, 2400, 3200, 4800, 6400, 8000, 9600 bps ♦ - ♦
U 12800 bps ♦ - ♦
MIL-STD-188-110B C PSK/
QAM		 75, 150, 300, 600, 1200, 2400, 3200, 4800, 6400, 8000, bps ♦ - ♦
MIL-STD-188-110A
§ 5.3		 C PSK 75, 150, 300, 600, 1200, 2400 bps ♦ ♦ ♦
U 4800 bps ♦ ♦ ♦
STANAG 4415 C PSK NATO robust: 75 bps ♦ ♦ ♦
STANAG 4285 C PSK 75, 150, 300, 600, 1200, 2400 bps ♦ ♦ -
U 1200, 2400, 3600 bps ♦ ♦ -
STANAG 4481 PSK C PSK 300 bps ♦ ♦ -
STANAG 4481 FSK U FSK Single channel: 75 bps ♦ ♦ -
Multi-channel: 75 bps selectable carrier ♦ ♦ -
FSK Variable U FSK Data Rates: 50, 75, 100, 150, 200, 300, 400, 600, 1200 bps
Mark & Space Frequency: 350 to 3000 Hz		 ♦ ♦ -

 

General
All Waveforms Carrier capture range ±200 Hz. Sync-on-Data
Frequency tracking of up to 75 Hz changing at 3.5 Hz per second (triangular sweep)
BIT Comprehensive BIT (Built-In-Test), Continuous error detection
Presets 20 Factory Presets, 10 Custom Presets
AGC Control Transceiver AGC control is necessary for optimum performance of QAM W/Fs
Remote Control All W/Fs and 2G ALE settings are remote controllable via Remote Control Port
Autobaud All PSK waveforms except for STANAG 4285 & 4529. Sync-on-Data capability
Tone Excision Narrowband Interference cancellation of up to 4 signals

 

Software Option Characteristics

ALE 2G

MIL-STD-188-141B
APPENDIX A, B &
FED-STD 1045
FED-STD 1049

 Automatic Link Establishment 2nd Generation (2G ALE)
Occupancy Detection: MS 110A/B, S 4539, S 4285, S 4415, S 4529, S 4481, FSK, 8-FSK, SSB Voice
Protocol: Calling, AMD, DTM, Excluding: DBM, AQC-ALE
  • Link Quality Analysis (LQA)
  • Scanning (2 or 5 channels per second)
  • Selective Calling
  • Automatic Sounding
  • Automatic Hand-Off to Internal Modem
The unit may already support a particular radio protocol. If not, the radio control protocol must be made available
to AT Comms for integration & testing.

 

Interfaces
DTE (Data) Port RS-422 balanced, RS-423, RS-232 unbal., MIL-STD-188-114 compatible & EIA 530A compliant (DB25 connector)
Half & Full Duplex operation, Sync, standard async and high-speed mode supported:
  • Synchronous: Data Rate: 50, 75, 100, 150, 200, 300, 400, 600, 1200, 1800, 2400, 3200, 3600, 4800, 6400, 8000, 9600 bps, Clock: Internal / Ext., data polarity: norm / inv.
  • Asynchronous: 75 to 115200 bps, Full Duplex, 5/6/7/8 bit data, 1, 2 stop bits, Flow ctrl: CTS/RTS, data polarity: norm / inv.
Remote Control Port RS-485 Multi-drop, RS-232D (DE9 connector, male):
Data Rate: 1200 to 115200 bps, 1 or 2 stop bits, 8 bit character lengths
Flow Control CTS/RTS, Protocol: RM4 Control Protocol (proprietary)
Ethernet Data & Control, 10/100 Base T, RJ 45 connector, embedded TCP/IP Stack, Protocol: RM4 Ctrl Protocol
F / Panel 8 bit-colour status LED indicators on front panel:
  • DTE, REM Ctrl / LAN, RADIO Ctrl connection status
  • Mail (AMD), Modem & ALE, Voice (ALE voice call) activity status, Power indicator
Radio Control Port RS-232 (DE9 connector): 75 to 115200 bps, 1 or 2 stop bits, 7/8 bit character lengths.
Supports for various radio control protocols are built-in. See the AT Comms 2G ALE Product brochure for more details.
Radio Audio Port Input Audio: 600 Ohm balanced, –20 to +15 dBm without adjustment
Output Audio: Balanced, –40 to +10 dBm (PMP) adjustable into 600 ohm load
Keyline: Open collector to ground (<45 volts, 50 mA) & non-polarized contact closure (<45 V, 200 mA)

 

Installation Environmental
Weight 1.7 kg (approx.) Temperature -30°C to +70°C (operating)
Colour Black powder coat Humidity 0 to 90%, non-condensing
Size 41.1 x 212.7 x 159.0 mm (h x w x d),
Front panel height : 44.1 mm		 Shock MIL-STD-810E Method 516.4,
Procedure 1, Funct. (40G, 11 ms)
Power 87 to 267 V AC, 47 to 440 Hz
6 to 36V DC		 Vibration MIL-STD-810E Meth. 514.4, Cat. 9,
Shipboard
Rack Mounting 1 unit in ½ 19” Rack slot EMC MIL-STD 461-E
2 units side-by-side on shelf Safety IEC/EN 60950

RM4 HF - Data Modem - 2G - ALE - Naval - Military