5
460989001B
Wiring
Note:
For UL installations, refer to section UL Listed Installations on
page 8.
Supervised (Software Configurable) Alarm Inputs
Wire the I1 and I2 inputs across pins 1 & 2 and 3 & 4 of J15 using a twisted
pair cable, 30 ohms maximum. Terminate each of these inputs with two (2)
1k (1000) ohm resistors (1% tolerance - 0.25 watt).
Note:
Resistors must be installed as shown in the SDC wiring diagram
if the installation requires supervision.
SDC input wiring
The two (2) inputs available on the SDC are software configurable alarm
inputs that can be used for alarm device monitoring. Each of these inputs
can be configured, via the Access Control software, as either N/O (normally
open) or N/C (normally closed) in combination with either supervised or
unsupervised wiring. These alarm inputs are connected using Inputs 1 and 2.
Each input that is configured as a supervised alarm must also be terminated
with two (2) 1K (1000) ohm resistors (1% tolerance - 1/4 (0.25) watt. N/O
and N/C alarms are terminated identically). Resistors are provided with the
module.
Install the resistors as close to input device as possible. For cable length
limitations, refer to Specifications.
Upstream Communication
The Single Reader SDC Interface Module uses Port 1 to communicate to the
Intelligent System Controller.
Port 1 is a 2-wire RS-485 interface, that requires the following type of RS-
485 cable: 24 AWG (minimum) twisted pair (with shields). The main run
RS-485 cable should be no longer than 4000 feet [1219 m], 100 ohms
maximum (Belden 9841, West Penn, or equivalent). The drop cables (to
downstream devices) should be kept as short as possible, no longer than 10
feet.
The RS-485 communication is asynchronous, half-duplex, using 1 start bit,
8 data bits, 1 stop bit.
Notes:
The (EIA) Electronic Industries Association standard defines
RS-485 as an electrical interface for multi-port communications
on a bus transmission line. It allows for high-speed data transfer
over extended distances (4000 feet [1219 m]). The RS-485
interface uses a balance of differential transmitter/receiver to
reject common mode noise. For increased reliability over the
extended distances, End-Of-Line (EOL) termination is required.
RS-485 must be terminated at both ends of the RS-485 line
(bus). Terminating the line provides a more reliable
communication by minimizing the signal reflection and external
noise coupling. Each component provided has an on-board
terminator. The installer should determine which device is at the
end of the communication line.
Relay Outputs
The Single Reader SDC Interface Module contains two (2) form-C dry-
contact relay outputs, Relay 1 & 2 (K1 & K2). K1 is rated at 5A 30 VDC;
K2 is rated at 1A 30 VDC.
To wire the K1 and K2 outputs, use sufficiently large wires for the load to
avoid voltage loss.
Transient clamping must be provided to protect the output contacts and to
reduce EMI emissions. For AC-powered devices, use MOV across the load.
For DC-powered devices, use a diode across the load.
Input Resistor Table
Alarm Zone
Contact NC
Alarm Zone
Contact NO
Normal
1K
25%
2K
25%
Alarm
2K
25%
1K
25%
Fault – Line Short
0 – 50
0 – 50
Fault – Line Open
15K –
15K –
Fault – Foreign
Voltage
50 – 750
1250 – 1500
2500 – 15K
50 – 750
1250 – 1500
2500 – 15K
