Elatec TWN4F8 User Manual

Transponder Reader

TWN4 MultiTech 3 LF

Quick Start Guide / Integration Manual

Rev. 3.0

Elatec GmbH

1. Introduction

The transponder reader TWN4 MultiTech 3 LF is a device for reading and
writing RFID transponders. There TWN4 MultiTech 3 LF has a working
frequency of 125 kHz.

2. Getting Started

2.1 Cable Connection

In order to start operating a TWN4 MultiTech 3 LF transponder reader, it
simply has to be connected to a host.

2.2 Power Up

Once a TWN4 reader is connected to the host, it detects the type of
communications cable (USB or RS232), with which it is connected to the
host.

Additionally, the RS232 is sending a version string via RS232 to the host.

2.3 Enumeration (USB Only)

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.

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2.4 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 transponder reader modules 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.

2.5 Normal Operation

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

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Elatec GmbH

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.

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