RDAO-3 Optically Isolated
Wiegand card reader DA Instructions
The RDAO-3 is 3 port, Wiegand reader distribution amplifier with optically isolated inputs and outputs for
access control systems. All three ports are optically isolated from one another which prevents ground
loop caused data corruption issues. The RDAO-3 Monitors the LED outputs of the access control
panels and outputs an LED indication of “access granted or denied”
Reader Input
The RDAO-3 accepts one-way data standard Weigand card readers only. The RDAO-3 supports one or
two LED indicators. The reader power can also be configured for 12vdc or 5 vdc via an onboard jumper.
See figure 1.
Power Reader Locally Input
The Reader can be powered near the site and this input is used for that purpose. The reader power
source jumpers must be set for local. See figure 1.
Reader Power
The reader power can be supplied from a local power supply or by any one of the three connected access
control panels. See jumper settings in figure 1.
Data outputs
Whatever data comes out of the Wiegand reader will appear at the terminals of the D0 and D1 terminals
of the access control panel outputs. Connect these outputs to the access control panel reader inputs. See
figure 1. Note- no card read data is stored in the RDA1.
Panel connections
Note- 12vdc power must be supplied to the RDAO-3 form EACH connected access control panel or the
RDAO-3 will not transmit card read data. Connect the 12vdc power, data 0, data 1 and LEDs as shown in
figure 1.
LED signals
All LED inputs are normally high. The inputs to the RDAO-3 from the access control panels can be 5v or
12v. When a valid card read is detected by any of the 3 “green LED” inputs going low, the RDAO-3 will
send a “green LED” signal to the Wiegand reader green LED terminal (logic low). If an invalid card read is
detected by any or all of the 3 “red LED” inputs going low, the RDAO-3will send a “red LED” signal to the
Wiegand reader red LED terminal (logic low). See figure 1 For connections. You can also tie the Door
release signal via a relay from each panel to the Green LED input to display a valid card read on the
reader from any panel.
Cabling
Run a #22 6 conductor shielded from the Wiegand reader to the RDAO-3. Run up to 3 each #22 6
conductor shielded cables from the RDAO-3 to each access control panel. The shield can be used as a
common.
Grounding jumper
The RDAO-3 can be grounded locally to whichever power source is selected. This is useful if vicinity area
lightning strikes are frequent and are problematic. Note- if grounds between the selected reader power
source and this ground point are at different potentials, data corruption may occur.
