APR250 User Manual
24/03/21
Page 14 of 49
5 Operating states
The APR250 has several operating states concerning display status and communication
possibilities over USB. The following chart shows the different states.
When the reader is switched on and it is connected via USB, it works in
CDC-Mode
. That means
a virtual comport is created on the computer and it is possible to send commands to the device
via a serial port connection. In this state the mass storage mode is not activated, it is not possible
to copy files to or from the APR250.
After the configurable switch-off-time (default = 60 seconds) has elapsed, the reader enters
Suspend-Mode
when a USB cable is connected. The display is switched off but communication
is still possible. In this state the blue LED on the right above the display is flashing in cycles of
one second. The device will not enter sleep mode as long as USB is connected and the battery
is still charging. The red LED flashes in intervals of one second, indicating that the battery is being
charged. After the battery has been charged completely, the reader enters sleep mode after a
timeout of 60 seconds.
If the APR250 is connected to USB while it is switched off, the MSC mode is activated. Then the
reader is attached to the computer as a mass storage device and file transfer is possible. Once
the key is pressed, the device will switch on and use
CDC-Mode
right away. When pressing
for at least two seconds while USB is connected, the APR250 will enter
SD-Card Mode
as well.