INSTALLATION AND OPERATION INSTRUCTIONS
INTRODUCTION
Thank you for purchasing your American Fibertek MTX-81B multimode contact closure transceiver.
Please take a few minutes to read these installation instructions in order to obtain the maximum
performance from this product.
FUNCTIONAL DESCRIPTION
The MTX-81B operates as half of a transceiver pair for the transmission of eight dry latching contact
closure signals. Four contact closures are transmitted in one direction on the link with the remaining
four contact closures transmitted in the opposite direction. It is designed to operate with the MRX-81B
or RRX-81B contact closure transceiver over one multimode fiber optic cable. The MTX-81B
transceiver has a user selectable switch that allows the contact outputs of the unit to be maintained
unchanged through loss of optical or electrical power at the MTX-81B. The MTX-81B transceiver also
includes a recessed button to clear all contacts to a default state.
The MTX-81B converts four contact closure inputs into an optical output using a 1310 nm wavelength
source. The MTX-81B also converts an optical input from the MRX-81B or RRX-81B into four contact
closure outputs using a 1550 nm wavelength detector. The MTX-81B operates on 50 um or 62.5 um
multimode fiber. The 81B Series product is designed to operate over an optical loss budget range of 0
to 12 dB when using 62.5 um fiber. Refer to the data sheets for detailed performance specifications.
This unit is contained in a compact and rugged aluminum housing with internal dc voltage regulation.
The detachable terminal blocks and LED indicators provide for easy installation and monitoring of
contact closure and power. The MTX-81B is designed for mounting as a modular stand alone unit. For
a rack mounted version please see the RTX-81B.
INSTALLATION
THIS INSTALLATION SHOULD BE MADE BY A QUALIFIED SERVICE PERSON AND SHOULD
CONFORM TO THE NATIONAL ELECTRICAL CODE, ANSI/NFPA 70 AND LOCAL CODES.
Mount the unit to a secure surface using #8 (3mm) hardware in four places. See the drawing on the
next page for mounting dimensions. Be sure to allow sufficient room for the required minimum bend
radius of the fiber cable used.
POWER SOURCE
THIS PRODUCT SHALL BE POWERED BY A LISTED CLASS 2 POWER SUPPLY ONLY.
This unit requires a 12 volt DC power source for proper operation. In the USA and in Canada an
American Fibertek PS-12 is supplied with this unit. ANSI/NFPA 70 Class 2 wiring is recommended.
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