Impinj Speedway Revolution GPIO Box
Impinj designed the Speedway Revolution GPIO Box for use with the Speedway® Revolution reader to provide convenient access to the reader’s GPIO (General Purpose Input/Output)
port. The GPIO Box interfaces with the reader via a supplied HD15 cable, and separates each input and output signal to easy-access screw terminals. Neighbouring ground and power terminals accompany each signal terminal to easily connect three-wire devices. The GPIO Box also includes an on-board relay to interface with devices require high wattage or an open/short signal.
• Easy-access screw terminals
• Power and ground terminals for each input and output
• Each output can provide 250mA at 24V with optional
external universal power supply
• SPDT Relay output capable of 5A at 240VAC
• Ability to use reader-supplied 5V for low power digital
applications, including the SPDT Relay
• Highly visible LED indicators for each input and
output eases troubleshooting and diagnostics
• Access to reader’s RS-232 serial interface
Power Low Wattage Light Signals
In many applications it is helpful to utilize a light stack to indicate the status of an RFID system. By using the four
GPO Outputs of the Speedway Revolution, an application can turn on or turn off different lights depending upon
which antenna is operating, if the reader is currently writing tags, or if it has encountered an error while writing.
You may connect LED or low wattage (less than 6 W) lights directly to each OUT signal and either the neighboring
GND or Vcc depending upon whether you want the light to turn on when the GPO is high or low. Or, connect two
lights to the same signal by connecting one to Vcc and the other to GND. In this case, when the GPO signal is high,
one light turns on and when the GPO goes low, the other light will turn on.
Power High Wattage Devices and Using the Relay
By using the on-board relay, you can interface to, and control high wattage devices.
To use the relay, simply move the top jumper, labeled JGPO, on the GPIO Box board to the left two pins, labeled
RLY and RO1. This action connects the GPO1 signal from the Speedway Revolution to the control circuitry for the
relay. You can then connect the device with which you wish to interface to the three terminals on the top left of the
board. One connection will always be connected to the COM, or common, connection. The other two connections
will be either a short to COM or an open, depending on the value of GPO1. If GPO1 is low, then NC (normal
closed) is shorted; when GPO1 is high, NO (normal open) is shorted.
To power a high wattage light, connect COM to ground and NO to one terminal of a light. The other terminal of the
light should be connected to an appropriate power source.
When GPO1 is low, NO will be an open circuit and will not allow the light to turn on. When GPO1 is high, it will
short NO to ground and turn on the light. The relay can be switched even while using the 5V supplied by Speedway
Note: when using the relay, OUT1 signal will no longer operate and will always output as a high signal.
Using Speedway Revolution’s 5V Supply
A feature of the Speedway Revolution is the 5V supplied through the GPIO port. By using this power supply, you
may provide a power source to low-power logic devices without requiring a separate power supply. To utilize the
5V supply from the reader, move the bottom two jumpers to the left two pins. In this configuration, the row labeled
Jplus should have the jumper connecting the pins labeled 5V and Vcc. The row labeled Jminus should have the
jumper connecting the pins labeled RGND and GND.
Note: when using the reader’s supplied power source, the opto-isolation built within Speedway Revolution is
bypassed, which may cause signal degradation.