DD1000/SRM
DDAA1000/SRM

Discrete/Analog Wireless Multiplexer
for the 900 MHz ISM Band

Features

• Easy to implement

• Field configurable

• Automatic restart

• No special software required

• Point-to-point or point-to-multipoint

• Inexpensive to install—no wires to route or ditches to dig

The Data-Linc Group DD1000/SRM and DDAA1000/SRM wireless multiplexers offer applications the ability to transmit 4-20 mA and/or discrete signals without the cost or inconvenience of adding wires or additional devices.

The DDAA1000/SRM combines an analog/ discrete signal digitizer with Data-Linc Group’s SRM industrial grade license free wireless modems. The result is a simple to implement solution for I/O signal transmission.

Each DDAA multiplexer has eight discrete inputs and eight outputs, as well as eight analog (4-20 mA) inputs and outputs.

The DD1000/SRM is as described above but offers only the discrete function.

The radio section of the multiplexers incorporate the license-free 902-928 MHz spread spectrum ISM (industrial/scientific/medical) band technology used by the Data-Linc Group SRM Family of radio modems. These units are capable of wireless transmission up to 25 miles (40 km) with line-of-sight and an omni directional antenna. (Also available for the 2.4 GHz band.)

In the event of a communications link failure, discrete outputs will default to open, while analog outputs will default to 4 mA.

Please consult with a Data-Linc Group Applications Specialist by phone at (425) 882-2206, send your proposed application diagram to us via Fax at (425) 867-0865 or for review.

Applications

• Mining
• Water/Wastewater - monitor tank levels via
  4-20 mA analog signals and control pump
  contact closure via discrete signals
• Most types of discrete 4-20 mA applications

Download pdf (523K) print version of the Data Sheet for the DD1000/SRM & DDAA1000/SRM Discrete/Analog Wireless Multiplexer. (Requires Adobe Acrobat Reader to open.)

Download pdf (371K) technical article file Discrete/Analog Multiplexer, "Wireless Communication System for Stray Current Interference Testing"

DD1000/SRM and DDAA1000/SRM 900 MHz Band Specifications

System Configurations
Point-to-point, point-to-multipoint (1 Master multi-dropped with up to 8 addressable single channel Remotes)

Channel Functions
Analog. 4-20 mA standard, 24VDC max. Internal 8 bit
A/D yields 2% accuracy of 4-20 signals
Discrete Input. Dry contact closure-switch closure
detection
Discrete Output. Open collector— sync to ground
100 mA per channel 12-24 VDC

Operating Environment
Standard. 32° to 140°F (0° to 60°C)
Humidity. 0 95% non-condensing humidity

Connections
RF Antenna. Standard thread SMA female.
Supplied bench test 0 dB whip antenna
Optional. External omni directional or yagi antennas available.

Analog (4-20 mA input and output): 9 position pluggable terminal blocks
Pluggable terminal blocks standard wire size 12-26 AWG

Digital (Contact Closure input and output):
9 position pluggable terminal blocks
Pluggable terminal blocks standard wire size 12-26 AWG

Power: Barrel jack (2.0 mm center, 6.5 mm barrel)
120 to 12VDC barrel jack transformer included

Configuration: : 6 pin mini-din.
RS232 port used for reconfiguration of RF and
processor channel parameters.
Supplied programming cable and software CD with each Master unit.

Indicators
Power
CD (Carrier Detect)
Tx (Transmit Data)
Rx (Receive Data)
Status (Error Status, Master unit only)

Voltage and Current
Voltage: 12 VDC nominal, min 10.5, max 18VDC
Current: 160 mA idle, 660 mA peak on transmit

Enclosure
Standard. 18-gauge steel with mounting flanges
Weight
4 lb (1.82 kg) See diagram below.

900MHz Versions of DD1000/SRM and DDAA1000

DD1000/SRM/M (Master unit)
Discrete signal multiplexer with integral radio modem:
902 to 928 MHz license-free radio modem with 8 discrete Inputs and Outputs.

DD1000/SRM/R (Remote unit)
Discrete signal multiplexer with integral radio modem:
902 to 928 MHz license-free radio modem with 8 discrete Inputs and Outputs.

DDAA1000/SRM/M (Master unit)
Discrete and Analog signal multiplexer with integral radio modem: 902 to 928 MHz license-free radio modem with 8 discrete Inputs and Outputs as well as 8 analog Inputs and Outputs.

DDAA1000/SRM/R (Remote unit)
Discrete and Analog signal multiplexer with integral radio modem: 902 to 928 MHz license-free radio modem with 8 discrete Inputs and Outputs as well as 8 analog Inputs and Outputs.