915U-D Wireless Serial Modem

Key Features:

The ELPRO 915U-D Wireless Serial Modem is an RS-232 or RS-485 data modem Designed with
a long range, license-free 900-MHz or 2.4-GHz wireless transceiver to enable cost effective, two-way communications between serial devices

• 902–928 MHz frequency and 10 mW to 1W RF power
• 2.401–2.4835 GHz frequency and 1–100 mW RF power
• USB interface for ease of configuration
• Ability to construct complex networks using multiple repeaters and roaming features
• Adjustable over-the-air data rate for speed and range
• Reduced transmission latency for high speed control
• Superior receiver sensitivity and rejection to cut through interference
• Hardened encryption (AES 128, 192, and 256 bit) to ensure security of data
• Adjustable output RF power to keep signals within your plant
• Firmware upgradable locally and over the air
• Industrial temperature range ensures reliability in extreme environments
• Remote access and diagnostics eliminates time consuming site visits
• Voltage test point for RSSI measurement
• Sleep mode and frequency blocking

Product Details

Transmitter and Receiver


902–928 MHz, 2.401–2.4835 GHz

Transmit power

10 mW to 1W , 1–100 mW


Frequency hopping spread spectrum (FHSS)



Receiver sensitivity

–92 dBm @ 500 kbps, –98 dBm @ 250 kbps,

–102 dBm @ 125 kbps a

–96 dBm @ 250 kbps, –100 dBm @ 125 kbps,

–105 dBm @ 19.2 kbps

Data rate

500 kbps, 250 kbps, 125 kbps

250 kbps, 125 kbps, 19.2 kbps

Range (LoS)

40 miles (64 km)

7 miles (12 km)

Antenna connector

SMA female

Input and Output

Discrete output

RF link status 0.5A @ 30 Vdc relay

Serial Port

RS-232 EIA-232 via terminal block

RS-485 EIA-485 via terminal block with selectable termination resistor

Data rate (bps)

1200–230400 including PROFIBUS 31250, 45450, 93750

Serial settings

Baud rate, data bits, stop bits, parity, flow control

Protocols and Configuration

System address

4.2 x 10^9 possible addresses

Protocols supported


User configuration

USB interface

Configurable parameters

Master/slave, repeater, serial data items


 AES 128, 192 and 256 bit

LED Indication and Diagnostics

LED indicators RF link, RF TX and RX, RS-232 TX and RX, RS-485 TX and RX

Reported diagnostics RF, serial

Network management Via master radio to all remotes

Power Supply

Nominal supply  9–30 Vdc, over voltage and reverse wiring protected

Average current draw 150 mA @ 24 Vdc a, 100 mA @ 24 Vdc b

Transmit current draw 200 mA @ 24 Vdc a, 125 mA @ 24 Vdc b


EMC FCC Part 15; EN 301 489

RF (radio) FCC Part 15.247; ETSI EN 300-328

Hazardous area cUL, Class I Div 2, Groups A, B, C, D, Temp Code: T5

ATEX Zone 2, EEx nL IIC T5 II 3G, IECEX Ex nL IIC T5

Safety EN/UL 60950-1


Temperature rating –40 to 158ºF (–40 to 70ºC)

Humidity rating 10% to 90% noncondensing