S.I. Tech, Inc.Model 9304 - Twinax to Fiber Optic Multiplexer

IBM Systems 3/X & AS/400, & 5251 Controller

9304 Bit-Driver

Operation Mode:

Synchronous, half/full duplex, 1 Mbps serial bi-phase data each port

Input/Output Interface:

100 Ohm twinax bulkhead jack, IBM protocol

Number of Channels:


Transmission Line Interface:

2 ST fiber optic receptacles (SMA option)

Data link Speed:

5 Mbps

Transmission Distance:

2 Km (6600 ft.), (5 Km option)

Transmitter Output Power:

30 microwatts into 50 micron fiber

System Wavelength:

850 nanometers (1300nm option)

Receiver Sensitivity:

3 µw at 10-9 bit error rate

Operating Temperature:

0 °C to 50 °C

Metal Enclosure:

10.0" X 5.5" X 10.5"
(25.4 X 14 X 26.7 cm) (2 units can be rack mounted in 19" rack)


12 lbs. (5.54 Kg)

Input Power:

110/220 VAC, 50/60 Hz, 20 W
detachable power cord, power supply meets UL, CSA, VDE, & IEC requirements

230V Version:


S.I Tech Model 9304 multiplexer Bit-Driver is designed to work with IBM System 3/X, AS/400, and 5251 controller using twinax cable. Model 9304 Bit-Driver is a 4 channel twinax to fiber optic transmitter/receiver full duplex multiplexer product implementing IBM Protocol. Normal operating data rate is 1 Mbps on each port.

This fiber optic Bit-Driver product eliminates many disadvantages of twinax, especially EMI/RFI, ground loops (electrical isolation with fiber), high attenuation (high signal loss). limiting distance between nodes of system(5000 feet max twinax),and potential lightning damage outdoors between buildings.

S.I.Tech Model 9304 is a stand alone product allowing easy change from twinax to fiber. Simply disconnect twinax cables and connect to model 9304 input/output port. Model 9304 comes with power supply and status indicators.

S.I.Tech multiplexer can support one controller (one card from IBM 3/X andAS/400). IBM machines come with a various number of ports per controller. Check IBM equipment manuals for details. The number of ports is not fixed. While seven devices are supported per any given port, the total devices the controller card can support does not equal 7 x number of ports, e.g. System 36 has options such as:
First: 6 devices - one controller card.
Second: 28 or 36 devices - one controller card.
Third: 72 devices - second controller card. System 38 controller supports 32 devices.
Total 400 with 10 controller cards. AS/400 controller supports 40 devices. Total 400 with 10 controller cards.

S.I.Tech 9304 can support 28 users as long as only one controller card is connected to 9304 ports. S.I.Tech Model 9304 is totally transparent and uses IBM Protocol and addressing. If other than twinax cable is used, impedance matching transformers (balun) are needed.

Related products: 2836/9036/9302/9308/9328.

IBM and AS400 is a registered trademark of International Business Machines Corp.

UL Listed. 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.
©2012 S.I. Tech, Inc. All copy and images.