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The following applies to these products: SPX-7500.
This application note describes the connections necessary to convey supervised contact status over a Suprex®. The
configurations described in this application note should apply to most panels which utilize supervised contacts. When
connected as described, the Suprex® provides a supervised signal to the panel interface by reading the supervised status
of the contacts connected to the Suprex® Remote unit.
Theory of operation:
The access control panel is looking for a certain value of resistance connected to the supervised
contact terminals. The Suprex® Central unit will provide these resistance values locally at the panel so that the correct
supervised status is maintained. At the same time, the Remote unit must maintain supervision of the wires connected to
the relays and switches connected to the remote access point. The contact supervision is provided by the Remote unit.
The Suprex® system does this by comparing the value of programming resistor at the Central unit with the resistance seen
at the Remote interface terminals. When there is a difference in the two values, the Relay on the Central unit is activated.
There are two different
examples. One example is
monitoring a normally closed
contact at the Remote unit, and
the other example is monitoring
a normally open contact at the
Remote unit. In the examples
given, a normally closed
contact will require a
programming resistor of 1K and
a normally open contact will
require a programming resistor
of 2K. Other resistor values can
be used, but 1K resistors are
the most common. Other
resistance values will require
different value(s) for the
programming resistor(s).
+8 to +16 VDC
Ground
exp(+)
exp(-)
+5V Out
P R 4
P R 3
LED In
D1/Data Out
D0/Clock Out
Relay 4 N.O.
Relay 4 Com
Relay 4 N.C.
Relay 3 N.O.
Relay 3 Com
Relay 3 N.C.
Ground
Aux Output
Relay 2 Input
Relay 1 Input
+8 to +16 VDC
Ground
exp(+)
exp(-)
+5V Out
Relay 4 Input
Relay 3 Input
LED In
D1/Data In
D0/Clock In
Relay 2 N.O.
Relay 2 Com
Relay 2 N.C.
Relay 1 N.O.
Relay 1 Com
Relay 1 N.C.
Ground
Aux Input
Not Used
Not Used
+8 to +16 VDC
Ground
exp(+)
exp(-)
+5V Out
P R 4
P R 3
LED In
D1/Data Out
D0/Clock Out
Relay 4 N.O.
Relay 4 Com
Relay 4 N.C.
Relay 3 N.O.
Relay 3 Com
Relay 3 N.C.
Ground
Aux Output
Relay 2 Input
Relay 1 Input
Central
Remote
Remote
Central
Normally Closed Contact
Normally Open Contact
1K
1K
Input +
Input -
+8 to +16 VDC
Ground
exp(+)
exp(-)
+5V Out
Relay 4 Input
Relay 3 Input
LED In
D1/Data In
D0/Clock In
Relay 2 N.O.
Relay 2 Com
Relay 2 N.C.
Relay 1 N.O.
Relay 1 Com
Relay 1 N.C.
Ground
Aux Input
Not Used
Not Used
1K
1K
2K
1K
1K
1K
Input -
Input +
Application Note on using Supervised contacts with the Suprex® RS-485 Series
