The isolation of the Isolated Basic card (GN815 and GN816) is in line with the
limit for safe voltage and currents as mentioned above.
Table 12.5: Limit for safe voltage and currents (GN815 and GN816)
Input signal to input signal
±
140 V DC, 55 V RMS (low voltage
limit)
Input signal
-
to
-
chassis
±
70 V DC, 33 V RMS (low voltage limit)
Channel to chassis
±
70 V DC, 33 V RMS (low voltage limit)
Channel to channel
±
70 V DC, 33 V RMS (low voltage limit)
Nondestructive, to chassis (earth)
±
70 V DC, 33 V RMS AC (low voltage
limit)
-
+
ADC
Isolated channel
-
+
ADC
Isolated channel
Chassis
140 V DC,
55 V RMS
70
V DC,
33
V RMS
70 V DC,
33 V
RMS
70 V DC,
33 V
RMS
Figure 12.26:
Isolation of the Isolated Basic card (GN815/GN816)
12.3.5
Understanding the GN815 and GN816 input
The isolation of the GN815's and GN816's signal input channels are single
-
ended (also termed unbalanced isolated or unbalanced differential isolated).
This means that one signal of both inputs within one channel pair is directly
connected to the isolated channel ground (this is the outer signal of the BNC
plug). The other signal is connected to the conditioning amplifier.
A (simplified) schematic representation of the input channel of the GN815 and
GN816 can be found below.
GEN3i
244
I3763-3.1 en HBM: public
