User's Manual

OBID
®
Installation ID ISC.M02
FEIG ELECTRONIC GmbH Page 37 of 42 M20301-0de-ID-B.doc
E N G L I S H
8.4.3. Retuning the internal antenna: Trim capacitor C65
The antenna of the ID ISC.M02 can be detuned as a result of various ambient conditions such as
nearby metal objects (see Section 8.5). This detuning can be compensated to some degree using
the trim capacitor C65.
Fig.: 3.4.3-1: Trim capacitor for retuning the antenna
The integrated antenna can be retuned with the aid of an oscilloscope (bandwidth ≥ 20 MHz). To
do this, short the GND terminal of the oscilloscope probe with the probe point and hold it over the
circuit board of the ID ISC.M02. The probe then forms a measuring loop for the radiated magnetic
field of the ID ISC.M02. The distance between the oscilloscope probe and the ID ISC.M02 should
be between 0 and 3 cm.
Use the software command „RF-ON“ (0x6A) to turn on the HF field of the ID ISC.M02. A 13.56
MHz signal should be visible on the oscilloscope screen.
To tune the internal antenna, now set the signal amplitude of the 13.56 MHz signal to maximum
using trim capacitor C65.
Bild 3.4.3-2: Configuration for tuning the internal antenna
C73
J2
J3
X2
X3
X4
X1
J1
V2
V1
C65
Trim capacitor C73:
DO NOT CHANGE !!!
Trim capacitor C65:
Retuning the
internal antenna
ID ISC.M02
Turn C65 to set amplitude
to maximum