Elatec GmbH
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2.6 Detection of a Transponder
If a transponder is detected by the reader, following actions are performed
Send the ID to the host. By default, the USB device sends by
emulating keystrokes of a keyboard. A RS232 device sends the
ASCII code of an ID.
Sound a beep
Turn off the green LED
Blink the red LED for two seconds
Turn on the green LED
Within the two seconds timeout, where the red LED is blinking, the
transponder, which just has been recognized will not be accepted again.
This prevents the reader from sending identical IDs more than one time to
the host.
If during the two seconds timeout of the red LED a different transponder is
detected, the complete sequence restarts immediately.
2.7 Suspend Mode (USB Only)
The USB version of the transponder reader supports the USB suspend
mode. If the USB host is signaling suspend via the USB bus, the
transponder reader is turning off most of its power consuming peripherals.
During this operation mode, no detection of transponders is possible and all
LEDs are turned off.
Once the host is resuming to normal operation mode, this is also signaled
via the USB bus. Therefore, the transponder reader will resume to normal
operation, too.
