Black Cat Systems


Follow our tweets!

Home
Lost Reg Code?
News
Online KiwiSDRs
macOS Software
Windows Software
Ham Radio iPhone/iPad
Linux Software
Support/FAQ
Update Policy

USB Icom CI-V Interface

Radio Hobbyist Products

  22m Programmable Beacon Kit
  22m Part 15 Beacon Kit
  CW Keyer For Beacons Kit
  Jellyfish Transformer
  Cyclops Antenna Transformer

General Interest Programs

  Atomic Mac/PC
  Audiocorder
  Audio Toolbox
  Black Cat Timer
  Diet Sleuth
  iUnit
  Graffikon
  Graph Paper Maker
  Health Tracker
  Image Resizer
  Knitting Wizard
  Label Wizard
  Prog Audio Gen
  Sound Byte
  Synth 76477

Amateur Radio Programs
  AirSpyHF+ Server
  Audiocorder
  Black Cat Absolute ACARS
  Black Cat ACARS
  Black Cat ALE
  Black Cat ALE Vacuum Cleaner
  Black Cat NetFinder
  Black Cat GMDSS
  Black Cat HF Fax
  Black Cat SSTV
  Black Cat NAVTEX SITOR-B
  Carrier Sleuth
  Cocoa 1090
  Cocoa RTL Server
  DGPS Decoding
  DX Toolbox
  Elmer
  MatchMaker
  KiwiKonnect
  KiwiSDR Monitor
  KiwiSDR Sound Client
  MININEC Pro
  Morse Mania
  MultiMode
  sdrRewind
  RF Toolbox
  SDRuno Plugin
  SDRuno Equalizer Plugin
  SelCall
  Sonde

iPhone/iPad Apps
  ALE
  Atoms To Go
  dB Calc
  Clik Trak
  DGPS Decoder
  Drill Calc
  DX Toolbox
  Elmer Extra
  Elmer General
  Elmer Tech
  Feld Hellschreiber
  Field Strength Calc
  Function Generator Pad
  GMDSS
  Godafoss
  HF Weather Fax
  iAttenuate
  iFunctionGenerator
  iSoundex
  iSoundByte
  iSweep
  iUnit
  Morse Mania
  ACARS Pad
  Morse Pad
  NAVTEX Pad
  Packet Pad
  PSK31 Pad
  SSTV Pad
  Photon Calc
  Rad Map Tracker
  RF Link Calc
  SelCall Tone Gen
  Sound Byte
  Sound Byte Control
  Spectrum Pad
  SWBC Schedules
  Synth 76477
  Synth Motion
  Transmission Line Calc
  Weather Calc
  Wire Calc

iPhone/iPad Bundles
  RF Calculator Apps
  Ham Radio Decoder Apps
  Audio Utility Apps
  Shortwave Weather Apps
  Ham Radio Exam Study Apps
  Shortwave Decoder Apps

Android Apps
  ACARS
  Audio Function Generator
  
Audio Spectrum Analyzer
  
DGPS Decoder
  HF Weather Fax
  NAVTEX
  Rad Map Tracker
  SelCall Tone Gen
  Sound Byte Control
  SWBC Schedules
  Wire Calc

About Black Cat Systems
Site Map
Our software for Mac OSX
Privacy Policy
Press/Media
HFunderground
Apple /// Emulator

Macintosh Links
Shortwave Radio
Pirate Radio
Spy Numbers Stations
Science and Electronics
Ham Radio Software


   

Interfacing a Rockwell MDM-2001 HF modem via the Black Cat Systems MIL-STD-188C synchronous serial interface


USB Sync Interface

Black Cat Systems MIL-STD-188C synchronous serial interface

The Rockwell MDM-2001 is a programmable HF modem available on the
surplus market which can do a variety of advanced HF modes, including
MIL-STD 188-110A 39/16/single tone. This application covers using the
MDM-2001 in a single-channel receive-only configuration. Dual channel
and transmit operation are also possible, but the cables used would
change from the configuration described below.
Our interface does not support transmitting.

The modem used to develop this app note was model number 622-9653-009.

The modem has three connectors on the rear panel which must be
connected to the computer and radio used to operate the unit.

J1 - Synchronous serial data.
J2 - RS-232 (asynchronous) serial control port.
J3 - Radio interface (audio).

J1 is a DD-50 connected to a Black Cat Systems MIL-188C synchronous
serial adaptor with the following cable:

Rockwell MDM-2001    Black Cat Systems
J1                   MIL-188C adaptor
-----------------    -----------------
pin  name            pin name
---  -----           --- -----
2    RXD1            4   Data      
18   RX1 clkout      20  Clock
21   RX1 common      7   Ground

J2 is a standard 9-pin to 25-pin async cable:

Rockwell MDM-2001    IBM-PC
J2                   RS-574
-----------------    ------
pin name             pin name
--- -----            --- -----
2   txd              2   rxd
3   rxd              3   txd
7   gnd              7   gnd

J3 is an audio cable that will vary based on output from your
radio. Assuming you want to convert single-ended audio out of a
receiver into the differential audio the modem expects, a audio
frequency transformer with a center tap is required, and the following
cable will perform the job:

Receiver audio                  Rockwell MDM-2001
1/8" phono or RCA               J3
-----------------               -----------------
name                            pin name
----            transformer     --- ----
tip --------------+    +------- 1   RCV1_AUDIOA
                  | || |
                  | || +------- 14  RCV1_AUDIOC
                  | || |
ring -------------+    +------- 2   RCV1_AUDIOB

The MDM-2001 allows multiple modems to be addressed by a single serial
port attached to J2. Attempts to configure the MDM-2001 to run in
non-addressed mode were unsuccessful. The following are the
recommended jumper settings inside front panel door:

(9600 8/N/1, single modem addressed as unit 1):
S1: 1001111110 S2: 0001001000 (1 = ON, indent towards number)
Email your comments and questions to info@blackcatsystems.com

Last modified May 31, 2005