Mercury Security © 2014
EP1501
DOC 10107-0036
REV 1.07
Page 6
Reader Port 1 - OSDP Protocol Devices (2-Wire RS-485)
8. Input Circuit Wiring:
Typically, these inputs are used to monitor door position, request to exit, or alarm contacts. Input circuits
can be configured as unsupervised or supervised. When unsupervised, reporting consists of only the
open or closed states.
When configured as supervised, the input circuit will report not only open and closed, but also open
circuit, shorted, grounded*, and foreign voltage*. A supervised input circuit requires two resistors be
added to the circuit to facilitate proper reporting. The standard supervised circuit requires 1k ohm, 1%
resistors and should be located as close to the sensor as possible. Custom end of line (EOL)
resistances may be configured via the host software.
*
Grounded and foreign voltage states are not a requirement of UL 294 and therefore not verified by UL.
The input circuit wiring configurations shown are supported but may not be typical:
VO (12 Vdc)
GND
DAT
CLK
1
OSDP PROTOCOL DEVICE
9600 BAUD
ADDRESS 0
BZR
1
GND
GND
VIN
VO
DAT/D0
CLK/D1
1
LED
LED
BZR
OSDP PROTOCOL DEVICE
ADDRESS 1
9600 BAUD
REFER TO THE APPROPRIATE REMOTE SERIAL I/O DEVICE INSTALLATION MANUAL FOR ADDRESS
AND BAUD RATE SETTINGS. DO NOT TERMINATE ANY OF THE DEVICES ON THE RS-485 MULTI-DROP
COMMUNICATION BUS. EACH OSDP DEVICE MUST BE CONFIGURED WITH AN UNIQUE
COMMUNICATION ADDRESS. A MAXIMUM OF TWO OSDP DEVICES MAY BE CONNECTED TO READER
PORT 1.
(DEFAULT)
(DEFAULT)
TB4
TB3
TB2
FIRST READER PORT
GN
D
GN
D
12
Vd
c
TR
+
TR
-
GN
D
TR
+
12
Vd
c
GN
D
TR
-
TR+
TR-
FIRST READER PORT
1K,1%
1K,1%
1K,1%
1K,1%
Standard Supervised Circuit,
Normally Closed Contact
Standard Supervised Circuit,
Normally Open Contact
Unsupervised Circuit,
Normally Open Contact
Unsupervised Circuit,
Normally Closed Contact
IN2
IN1
TB
1
1
