American Fibertek MRM-1485-2F8 - Manual (Page 4)

4
FIBER INPUT / OUTPUT CONNECTIONS
The fiber optic connections are made via ST connectors located on the right side of the unit.
Please note that Fiber Out on the MRM-1485-2F8 is connected to Fiber In on the MTM-1485-
2F8 or RTM-1485-2F8. The reverse flow follows the same orientation.
VIDEO OUTPUT CONNECTION
The video output connection is made via a BNC connector on the right side of the unit. The 75
Ω
video output can be looped through typical baseband video inputs of switchers, recorders and
other equipment as required. For proper operation, the output must be terminated with 75
Ω. For
optimum performance the video cables should be the shortest length of coax practical.
DATA INPUT / OUTPUT CONNECTIONS
Data input and output connections are made via a terminal block on the right side of the unit.
Follow label on unit for proper orientation of RS485 data input and output. Please note that two
wire applications utilize the four wire Data Out + and Data Out - terminals. Also note that in four
wire installations Data In on the MRM-1485-2F8 becomes Data Out on the MTM-1485-2F8 or
RTM-1485-2F8 after going across the fiber. The reverse flow follows the same orientation.
DATA CONFIGURATION
The MRM-1485-2F8 is shipped from the factory in the RS485 4-wire configuration. In order
to configure the unit for RS485 two wire operation, the unit needs to be opened up and
several switch settings and jumper pins need to be modified using the internal
switch/jumper settings shown on the next page.
The MRM-1485-2F8 is shipped from the factory with internal data input and output 120
ohm terminations switched on. In order to remove the internal terminations, the unit
needs to be opened up and several switch settings need to be modified using the internal
switch/jumper settings shown on the next page.
See page 7 for an explanation of termination and offset bias requirements for RS485 data. To
open the MRM-1485-2F8, remove the screw on the bottom of the module. Also remove two
screws holding the end panel to the chassis on the side with the video and data connections.
Slide PCB assembly out of chassis to access the switch and jumper locations.