American Fibertek MT-926C User Manual
Page 5

5
TYPICAL SYSTEM DATA CONNECTIONS
The RS422 or RS485 four-wire interconnection between the MT-926C and the copper device to which it 
is attached is based on industry standard EIA terminology for the transmission of electronic data 
signals. Using this terminology, the driver of an electronic signal is labeled TX or Data Out. 
Correspondingly, the receiver of an electronic signal is labeled RX or Data In. Following this standard, 
the Data Out of the copper device is connected to the Data In of the MT-926C. The plus terminal of the 
copper device is connected to the plus terminal of the MT-926C and the minus is connected to the 
minus. The reverse flow of data from the MT-926C to the copper device follows the same pattern. Not 
all manufactures follow standard EIA terminology. Consult the installation instructions for your copper 
device if you are unsure which two wires are the drive (data out) wires and which two wires are the 
receive (data in) wires. 
Please note that Data In on the MT-926C becomes Data Out on the MR-926C or the RR-926C after 
going across the fiber. The reverse flow follows the same orientation. 
 
CONTACT CLOSURE INPUT / OUTPUT CONNECTIONS 
Contact Closure input and output connections are made via the terminal block labeled DATA 2 on the 
left side of the unit. See the drawing below for proper orientation of input and output connections. 
Please note that the far left pin on the connection drawing corresponds with the far left terminal block 
pin located closest to the top of the unit. For example, contact closure out is the pin located closest to 
the DATA 1 terminal block. 
 
DATA CONFIGURATION SWITCHES 
NOTE: This unit is shipped with Data Channel 1 in the RS485 4-wire configuration and Data 
Channel 2 in the contact closure configuration. 
 
For other configurations of data channel 1, please refer to the drawing below for changes to the default 
switch settings. These configuration switches are located on the right side of the unit and can be 
modified without opening the unit. 
 
