Mercury MR50 connections - Synergis Cloud Link

As part of your installation, you might need to include a Mercury MR50 interface module.

NOTE: For UL certified installations, the output from the MR50's K2 relay must not leave the room of installation and must be shorter than 30.5 m (100 ft.).

The following diagram demonstrates how to connect the module.

A	Reader connections	Connect one reader. NOTE: The wire colors in the illustration refer to "pigtail" HID readers; the information in parentheses refers to "terminal block" HID readers.
B	RS-485	RS-485 bus connection to other Mercury modules.
C	Line termination	For modules at end of line, install jumper J4 (MR50) or J1 (MR50-S3) for 120 Ohm line termination.
D	Address jumpers / DIP switches	Used to set the device address. For more information on address settings on the Mercury module, refer to the manufacturer's instructions.
E	Power In	Connect + to VIN (observe polarity). Connect - to GND. Use 20 AWG wires minimum.
F	Tamper input	MR50: Normally closed switch (J3) MR50-S3: Normally open switch (J2)
G	Relay outputs	MR50: Relay 1: 5A inductive, 0.6 PF Relay 2: 1A inductive, 0.6 PF MR50-S3: Relay 1: NO: 5A, NC: 3A inductive, 0.6 PF Relay 2: 1A inductive, 0.6 PF
H	Resistors	For OSDP integrations, prevent readers from misinterpreting noise on a non-driven RS-485 line as data by installing a 1k ohm pull-down resistor from D0 to GND on TB4. For wiring distances over 10 meters, install a 120 ohm termination resistor between D0 and D1, as well as between A (-) and B (+) on the RS-485 bus of the last connected reader. To find out whether you need to add a 1k ohm pull-down resistor between D0 and GND, see [KBA-78953] Communication issues between OSDP readers and some Mercury hardware.