Mode Of Operation; Operating Mode; Power Up; Enumeration - Elatec TWN4 MULTITECH 2 BLE User Manual

5 MODE OF OPERATION

5.1

OPERATING MODE

In order to start operating TWN4 MultiTech 2 BLE, 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
Once TWN4 MultiTech 2 BLE is connected to the host, it detects the type of communications cable (e.g. USB or RS-232), with which
it is connected to the host. In case of RS-232: Additionally, the RS-232 is sending a version string via RS-232 to the host.
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, where both LEDs are
turned off.
5.4

INITIALIZATION

After powering up and enumeration (in USB mode), the device is turning on the built-in transponder reader logic. The green LED is
turned on permanently. Some RFID readers need some kind of initialization, which is performed in this step. After successful
initialization, the device sounds a short sequence, which consists of a lower tone followed by a higher tone.
5.5

NORMAL OPERATION

As soon as the reader has completed the initialization, it is entering normal operation. During normal operation, the reader is searching
for a transponder continuously.
5.6

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. An RS-232 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.
5.7

SUSPEND MODE

The USB version of the RFID reader supports the USB suspend mode. If the USB host is signaling suspend via the USB bus, the
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
reader will resume to normal operation too.
© 2021 ELATEC GmbH – TWN4 MultiTech 2 BLE user manual DocRev3 – 07/2021 Page 6 of 11