S.I. Tech, Inc.Model 2128 - Optical Mini Multidrop Bit-Driver®
Operation Mode: Asynchronous half duplex
Input/Output Interface: RS-485, 2 wire port operating up to 200 Kbps or DB-9 Connector
Transmission Line Interface: ST connectors are standard for interfacing with fiber optic duplex cable (SMA option)
Optical Power into a 62.5 Micron Core Optical Fiber:
10 microwatts, 13 dB power budget @ 850 nanometers (1300 nm option)
Receiver Sensitivity: 500 nanowatts at less than 10-9 bit error rate. 10 microwatts max.
Operating Temperature: 0 °C to 50 °C
(-40 to +70 °C option-MM Fiber)
Metal Enclosure: 5.5 x 2.3 x 1.0 in (with flange)
(13.97 x 5.84 x 2.54 cm)
Panel or DIN rail mounting option
Weight: 0.4 lbs (182 grams)
Input Power: External with power supply
(S.I. Tech #2121 - 110 VAC to
12 VDC)
230 Volt Version: Use S.I.Tech 2164 power supply


  • RS-485 Multidrop
  • Various speed options up to 200 Kbps (Factory Set)
  • Flange Mounting
  • Multimode or single mode
  • Asynchronous, simplex, half, full duplex

Fiber ports repeat data through the 2128 and drop/insert data on the RS-485 port. The RS-485 port inserts data onto both fiber ports and gets data dropped from either fiber port.


Model Number Description
2128 Multimode to Multimode, ST Connectors
2128-MM-SM Multimode to Single Mode, ST Connectors
2128-SM-SM Single Mode to Single Mode, ST Connectors

Meets FCC requirements of Class A, Part 15 Computing Devices Standard.
Specifications subject to change without notice.

View Complete Technical Data Sheet (PDF)


Contact Information: Phone: 630.761.3640 Fax: 630.761.3644 Email: sales@sitech-bitdriver.com
S.I. Tech, Bit-Driver®, and Fiber Cluster® are registered trademarks of S.I. Tech, Inc.
©2015 S.I. Tech, Inc. All copy and images.