American Fibertek MR-944C - Manual (Page 5)

5
TYPICAL SYSTEM DATA CONNECTIONS
The RS422 or RS485 four-wire interconnection between the MR-944C 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 MR-944C. The plus terminal of the
copper device is connected to the plus terminal of the MR-944C and the minus is connected to the
minus. The reverse flow of data from the MR-944C 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 MR-944C becomes Data Out on the MT-944C or the RT-944C after
going across the fiber. The reverse flow follows the same orientation.
DATA CONFIGURATION SWITCHES
NOTE: This unit is shipped with Data Channel 1 in the RS485 4-wire 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.