LANGER EMV-Technik E 1, Руководство пользователя

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LANGER
EMV-Technik
DE-01728 Bannewitz
mail@langer-emv.de
www.langer-emv.de
E1
2.2.3 Measurement set-up with SGZ 21 to inject burst current with field sources
The field sources are connected directly to the "Burst output" (Figure 2) of the SGZ 21 via the generator and
extension cables. Magnetic field sources are always connected via two poles (Figure 7).
Apart from the field sources themselves, the connecting cables also generate fields that may couple to the
device under test and affect the measurement result. Cables should thus always be kept away from the
device under test if possible.
2.3 Sensor
The S31 sensor (Figure 8) is a digital probe head to transmit binary signals from the device under test. The
sensor has a three-pin shrouded header (RM 2.5 mm). One pin of the shrouded header is the 3.5 V auxiliary
power supply. The second pin is the ground pin. The third pin is the input of the probe head. The sensor
input is connected internally to a digital IC input. This is connected to digital signals, VCC (</= 5 V) and
ground inside the device under test. The IC output supplies an optical transmitter. The transmitter is
connected to a 2 mm conical socket to accommodate a 2.2 mm plastic optical fibre (LWL). The light signals
from the sensor are transmitted to the "LWL" counter input of the SGZ 21 via an optical fibre.
The level changeover switch allows the signal to be negated.
The sensor can be used in two different ways:
a) to detect logic signals in the device under test
b) to detect disturbances in the device under test
to a) It is helpful if important signals (Reset, CE) of the device under test are monitored so as to find the
causes of problems in immunity investigations with the SGZ 21. When using a conventional oscilloscope
probe head, the disturbances are led to the oscilloscope via the probe head. The disturbances would affect
the oscilloscope. In addition, the probe head would change the disturbance current paths of the device
under test and thus falsify the measurement results. This is the reason why probe heads with an optical
fibre connection have to be used. The S31 sensor is such a probe head.
to b) The IC input of the S31 sensor has an immunity level that can be used to detect disturbances in the
device under test. The sensor's sensitivity to disturbance pulses depends on the sensitivity of the __00 IC
(four NAND gates) that is mounted on it. The user can define the sensor's sensitivity by selecting the IC to
be mounted from a certain IC family.
Figure 7: SGZ 21 with BS°04DB magnetic field source.
Depending on their type,
field sources for electric
fields are connected via one
pole or two poles (Figure 31).