User's Manual

LF Transmitter Output

Configuration and Operation 5-9

3. Set the wanted TAP voltage to the value required by application (90V recommended for most

cases):

NVA=xx<Enter>,xx - is the value in Volts

4. Set the wanted C9 threshold voltage to the value required by application (40V recommended

for most cases):

NVT=xx<Enter>,xx - is the value in Volts

5. To start the Exciter self calibration process send

:CONFIG:EXCITER n<Enter>

Wait about 30 seconds for the process to finish. If the returned error code is not 00, refer to

RFID System S21 Reference Guide for the command operation and error codes description.

6. Check the auto-diagnostic feature, by typing:

:DATA:PURGE<Enter>

:TEST:EXCITER n<Enter>

where n is the decimal address (1, 2, 3,...) of the Exciter that you want to test.

The response should be 00, meaning that the TAP voltage is higher than C9 threshold, and the

Reader should contain in the buffer a message from the Test Tag.

7. Check the excitation field pattern by monitoring the TAP voltage with the Oscilloscope. Make

sure that the TAP voltage is set to the correct value.

8. Turn off the excitation field, by typing:

C<Enter>

The TAP voltage amplitude should become zero.

9. Turn on the LF field again, by typing:

B <Enter>

The TAP voltage signal should have the same value and pattern as measured in Step 7.

10. Repeat Steps 1 to 9 (inclusive) for each Exciter that is connected to the Reader.

11. Power up all Exciters connected to the Reader.

Note When more than one Exciter EX21 is used to create a wider excitation zone, a magnetic coupling

can appear. The phenomenon is explained in Chapter 4, Setup Guidelines in the RFID System S21

Technical Guide. The coupling generates an unwanted amplitude modulation with a frequency of

several Hertz, the modulation depth depending directly on the coupling. The installer has to

monitor the TAP signal and adjust the position of the EX21 frames to obtain a minimum unwanted

modulation depth. To do that, the installer can increase the distance between frames, level the

frames in the same plane, or place the frames with the shorter sides (1m) in parallel. As a general

guideline, the minimum amplitude of V

TAP

due to unwanted modulation should be more than two

thirds or 67% of the application required V

value.