DCB SR-04 Statistical Multiplexer
Wireless 4 channel

  • Low Cost
  • Up to 15 mile range with optional antennae
  • 900Mhz ISM band
  • No license required
  • Port speeds to 57.6 Kbps
  • Network Management Port
  • Remote set up and testing
  • Composite link speed is 57.6 Kbps
  • 4 async channels
  • Test message generation
  • "Data Scope" functions to allow monitoring of any data port
  • "Copy Command" for remote training
  • Composite link is error corrected


Port Specifications
Network Specifications
Operating Modes
Indicators (front panel)
Network Management Port
Network Management Port Commands




The SR-04W statistical multiplexer concentrates 4 asynchronous channels over a single radio link. All port parameters are set with an asynchronous terminal connected to the network management port or port 1. Set-up procedures are menu driven and fully explained on screen. All configuration parameters are battery supported through power outages.

The asynchronous ports can be individually set for speeds to 57.6 Kbps. Hardware (CTS/Busy high or low) or software (Xon/Xoff even, odd, mark, space or transparent) flow control is also set on a port by port basis.

The SR-04 composite is a wireless link that runs at 57.6 Kbps. It transmits on the 900 Mhz license-free ISM band. The link radio modules are easily configured using a terminal or PC connected to the network management port or port one. Range is 1000 feet indoors using supplied antennae or up to 15 miles with optional external antennae.

The network management port includes local and remote configuration commands. The Show Configuration Commands allow the system manager to view the configuration settings of both the local and remote SR-04W Multiplexers. Network management features include port and composite loopbacks, capture of a remote or local port, send a test message to an individual local or remote port, set multiplexer ID for node identification and a built-in "data line monitor" which allows the monitoring of the transmit or receive lines at the local multiplexer. A unique feature of the SR multiplexer is the Copy Command. This command allows a trainer at the host site to "copy" any local or remote port to view exactly what the user is entering. This feature can save thousands of training dollars by eliminating travel expenses.

The SR-04W multiplexer has a side panel access for firmware cartridge installation. This feature simplifies installation of upgrades for new features and functions.

The SR-04W is compatible with virtually all async terminal-printer/computer links. You can save thousands of dollars by concentrating your terminals on one wireless link while delivering top performance. In addition, with features like the loopback, test message, ID, monitor and copy commands, you can take charge of your network like never before.


Asynchronous Statistical Multiplexing
4 channels
All ports can be 57,600 bps
Port Specifications
Data Format
1 Start bit
8 Data bits including parity if used
1 Stop bit
10 Bits total
Rates: 300, 1200, 1800, 2400, 4800, 9600, 19200, 57,600 bps individually selectable per port
Interface: CCITT V.24, RS-232-D
Connectors: RJ-45 (8-wire)
Buffering: 64K dynamically allocated
Port Flow Control: Set on an individual port basis
Clear to Send
Busy High
Busy Low

Network Specifications

900Mhz ISM Band:

Rate: 57.6 Kbps Asynchronous
Frequency Range: 902-928 Mhz
Spreading Function: Frequency Hopping, 100 channels
Output Power: 1 W (+30dBm)
Range: Standard Antennae 1000 Ft. (Up to 15 miles with optional antennae)

Operating Modes

Normal on-line multiplexing
Network loopback

Indicators (front panel)

Power, Multiplexing, Receive Error, Modem Ready, Option, Port 1 Setup, Loopback

Network Management Port

Interface: CCITT V.24, RS-232-D
Connector: RJ-45 (8-wire)
Can be mapped to Port 1
Network Management Port to terminal cable included

Network Management Port Commands

Help Screen
Remote Test Loop
Monitor Transmit
Monitor Receive
Network Loopback
Flow Control Active
Set Time

Show Configuration
Show Network
Configure Ports
Port Loopback
Device Type
Capture Port
Copy Port
Send Test Message
Activity Counters
Radio parameters are configurable through a command line interface


Power requirements: 120 VAC, 30-43 Watts, .25-.36 Amps
101/4" x 93/4" x 21/4"


External Antenna
Antenna Cable


Rear view of DCB SR-04W Multiplexer


DCB Products