The PR +5V pins can be jumped to the Data 0 OUT and Data 1 OUT Wiegand output pins to pull up the
voltage to 5VDC. The PR +5V pins are used when the Wiegand data voltage on the output side is below
5VDC or when the other Wiegand devices connected to the Wiegand output do not have their own pullup
resistors.#
When using Wiegand devices on the output side that operate the Wiegand data lines at a voltage other than
5V, the PR +5V pins should not be used. If the PR +5V pins are jumpered to the Wiegand outputs operating
at more than 5VDC, they will act as pulldown resistors and pull the voltage down to 5VDC. This will cause
the Wiegand data lines to not pass data.
If Wiegand signals are unable to be passed though the CVX-OPTW, check the following:#
The troubleshooting steps below assume 5VDC Wiegand devices
Common ground connections:#
•Wiegand input devices must share a common ground connection with the J1 header.#
•Wiegand output devices must share a common ground connection with the J2 header, unless they are
powered with the same power supply.#
Wiegand input data voltage levels:#
•Measure DC voltage between Data 0 IN and Ground, and again between Data 1 IN and Ground on the J1
header. Normally the voltage levels should be at 5VDC or equivalent high voltage if using Wiegand devices
that operate at higher voltages. #
•If the voltage levels are below 4.4VDC, then disconnect the Wiegand device(s) from the J1 header and
measure the devices while they are not connected to anything. The J1 header Wiegand inputs are open
collector and will be at 0VDC while no devices are connected. #
•If the voltage levels of the Wiegand device(s) are below 4.4VDC while it is not connected to other devices,
they the problem lies with that device and not the CVX-OPTW. This may be able to be recovered using
external pullup resistors. Connect a 1K to 2K through-hole resistor to the low data line and a 5VDC output.
This will pull the voltage up to 5VDC.If the voltage level for a Wiegand data line is below 1VDC, then the
line is clamped to ground and cannot be recovered. #
Wiegand output data voltage levels:
•Measure DC voltage between Data 0 OUT and Ground, and again between Data 1 OUT and Ground on
the J1 header. Normally the voltage levels should be at 5VDC or equivalent high voltage if using Wiegand
devices that operate at higher voltages. #
•If the voltage levels are below 4.4VDC, then disconnect the Wiegand device(s) and measure the voltage of
the Wiegand lines on each device separately (inlcudeding the CVX-OPTW J2 header). #
•If the voltage is between 4.4VDC and 1VDC then reconnect the Wiegand device(s) to the J2 header and
jumper the PR +5V pin. This will pull the voltage back up to 5VDC and allow Wiegand data to be passed. #
•If the voltage is below 1VDC on any of the Wiegand devices, then that line is clamped to ground and
cannot be recovered.
