ThingMagic Astra - Manual (Page 35)

Using GPIO
Astra User Guide 35
Using GPIO
The Astra Reader includes 12-pin GPIO screw terminal connector. This connector is used
to support four opto-isolated general purpose inputs and four opto-isolated general
purpose outputs. The values of the GPIO lines can be Get and Set using the RQL and the
C-API interfaces. See the respective guide for more details.
There are four open-collector outputs and four open-collector inputs.
Note
Devices using the GPIO lines must be NPN type devices and require external
power supply. .
Inputs
The four opto-isolated inputs support the following input levels:
V-low (Logic 0) = 0-0.8V
V-high (Logic 1) = 3-30V
5mA max current with 24V input
It is recommended that external devices guarantee a minimum pulse width of at least
100ms.
Outputs
The outputs sink up to 50mA, but do not source any power, external power is required.
The GPIO output lines effectively act as a switch.
In addition to the Input and Output lines, pins 10 and 11 duplicate the information provided
by the reader's activity LED indicating reader health and RF activity. RF activity can also
be monitored in this connector. See the section
Interpreting the Reader Indicator LED for
information about Reader activity and status.
These are the pin-outs of the 12-pin terminal connector (Pin 1 is closest to the LED):
1. Isolated-GND
2. GPIO Input ( GPIO_3 )
3. GPIO Input ( GPIO_4 )
4. GPIO Input ( GPIO_6 )