J3: Door And Rex Switch Connector; J4: Door And Rex Supervision Connector - UTC Fire and Security WIU-4 Installation Manual

10 Wiegand Interface Unit Four State (WIU-4)
Installation Manual

J3: Door and REX switch connector

The 6-pin connector, J3, is the door and REX switch
interface.
If the door or REX switch is set up as supervised (1K
resistor in series with switch between high and return pins,
1K in parallel with switch), the WIU-4 treats both the door
and REX switch as supervised and reports four states: cut
line, short circuit, closed circuit, and open circuit.
Note: To enable four-state supervision for the door and the REX,
install a jumper at position J4. Both points must be terminated
with resistors as shown in
If supervision is required for only one (the door or the REX),
then also insert a 1K resistor across J3, pins 3 and 4 or pins 5
and 6, as applicable.
If the door or REX is not set as supervised, the adapter
reports two states: open when there is no connection
between the high and return pins, or closed when a short
exists between high and return pins.
Table 1. J3 Door and REX switch connector
PIN Description
1 Power 12 VDC fused power, 250 mA maximum
2 Ground
3 Door (high) 5 VDC output
4 Door (return) 0-5 VDC input
5 REX (high) 5 VDC output
6 REX (return) 0-5 VDC input

J4: Door and REX supervision connector

The 2-pin connector, J4, is the door and REX supervision
connector. By default, a jumper is installed on pins 1 and 2
to enable 4-state supervision. Remove the jumper to
disable 4-state supervision and enable 2-state supervision.
Figure 4 on page 15.