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

5 MODE OF OPERATION

5.1

OPERATING MODE

In order to start operating TWN4 MultiTech M, 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 M 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

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, the device is turning on the built-in transponder reader logic. The green LED is turned on
permanently. Some 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 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. 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 module 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

TWN4 MultiTech M 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 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
module will resume to normal operation too.
© 2021 ELATEC GmbH – TWN4 MultiTech M user manual DocRev1 – 07/2021 Page 6 of 10