© 2021 ELATEC GmbH – TWN3 Mini Reader MIFARE NFC user manual DocRev1 – 10/2021
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5
MODE OF OPERATION
5.1
OPERATING MODE
In order to start operating TWN3 Mini Reader MIFARE NFC, it simply has to be connected directly to a host device.
5.2
POWER UP
In case of an external power supply unit is used, the following requirements must be satisfied:
•
Limited power source according to the safety norms listed in the respective declaration(s) of conformity
•
Short-circuit current < 8 A
5.3
ENUMERATION
This is only applicable for the USB version: Once the device has been powered up, it is waiting for completion of the enumeration by
the USB host. As long as the device is not enumerated, it is entering a minimum power consumption mode.
5.4
INITIALIZATION
After powering up and enumeration (in USB mode), the device is turning on the built-in transponder reader logic. Some RFID reader
modules need some kind of initialization, which is performed in this step.
5.5
NORMAL OPERATION
As soon as the reader module has completed the initialization, it is entering normal operation. During normal operation, the reader
module is searching for a transponder continuously.
5.6
DETECTION OF A TRANSPONDER
If a transponder is detected by the reader module, following actions are performed:
•
Send the ID to the host. By default, the USB device sends by emulating keystrokes of a keyboard.
Within the two seconds timeout, the transponder, which just has been recognized, will not be accepted again. This prevents the reader
module from sending identical IDs more than one time to the host.
If during the two seconds timeout a different transponder is detected, the complete sequence restarts immediately.
5.7
SUSPEND MODE
The USB version of the reader module supports the USB suspend mode. If the USB host is signaling suspend via the USB bus, the
reader module is turning off most of its power-consuming peripherals. During this operation mode, no detection of transponders is
possible. Once the host is resuming to normal operation mode, this is also signaled via the USB bus. Therefore, the reader module
will resume to normal operation too.
