Keri Systems MR52 - Manual (Page 6)

Mercury Security Corporation © 2011 MR52 DOC 10107-0015 REV 2.02 Page 6
9. Specifications:
The Interface is for use in low voltage, class 2 circuits only.
Primary power:
12 to 24Vdc ±10%, 550mA maximum (plus reader current)
12Vdc @ 450mA (plus reader current) nominal
24Vdc @ 270mA (plus reader current) nominal
Outputs:
6 outputs, Form-C, 5A @ 28Vdc, resistive
Inputs:
8 unsupervised/supervised, standard EOL: 1k/1k ohm, 1% 1/4 watt
2 unsupervised, dedicated for cabinet tamper and UPS fault
monitoring
Reader interface:
Reader power: 12Vdc ±10% regulated, 125mA maximum each reader
(jumper selectable and input voltage (VIN) must be 20Vdc minimum)
or
12 to 24Vdc ±10% (input voltage passed through) 125mA
maximum each reader
Reader LED output: TTL compatible, high > 3V, low < 0.5V, 5mA source/sink
maximum
Reader buzzer output: Open collector, 5Vdc open circuit maximum, 10mA sink
maximum
Reader data inputs: TTL compatible inputs or 2-wire RS-485
Communication:
RS-485, 2-wire 9600, 19200, 38400 or 115200bps
Cable requirements:
Power: 18AWG, 1 twisted pair
RS-485: 24AWG, 120 ohm impedance, twisted pair with shield, 4,000'
(1,200m) maximum
Alarm inputs: 1 twisted pair per input, 30 ohms maximum
Outputs: As required for the load
Reader data (TTL): 6 conductors, 18AWG, 500 feet (150m) maximum
Reader data (RS-485): 24AWG, 120 ohm impedance, twisted pair with shield, 4,000'
(1,200m) maximum
Mechanical:
Dimension: 6" (152mm)W x 8" (203mm)L x 1" (25mm)H
Weight: 11 oz. (312g) nominal
Environment:
Temperature: -55°C to +85°C, storage
0°C to +70°C, operating
Humidity: 0% to 95% RHNC