YOKOGAWA DL7480, User Manual

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2-3
IM 701450-51E
CAN Bus Signal Analysis Function
2
2.3 Connecting the Probe
Probes That Are Used
A differential probe is used when measuring CAN Bus signals.
Recommended model of differential probe (by Yokogawa): 701920 or 701922
Input Terminals
Connect the probe (or other input cables such as the BNC cable) to any of the input
terminals (4 terminals marked as CH1 to CH4 on the DL7440 and 8 terminals marked
CH1 to CH8 on the DL7480) located on the lower section of the front panel. The input
impedance is 1 M Ω ± 1.0% and approximately 20 pF or 50 Ω ± 1.0%.
CAUTION
• The maximum input voltage for 1-M Ω input is 400 V (DC + ACpeak) or 282
Vrms when the frequency is 1 kHz or less. Applying a voltage exceeding either
of these voltages can damage the input section. If the frequency is above 1
kHz, the input section may be damaged even when the voltage is below the
values specified above.
• The maximum input voltage for 50- Ω input is 5 Vrms or 10 Vpeak. Applying a
voltage exceeding either of these voltages can damage the input section.
DL7440
1M Ω /20pF 400Vpk CAT II 50 Ω 5Vrms, 10Vpk
CH
1
CH
2
CH
3
CH
4
DL7480
CH
7
1M Ω /20pF 400Vpk CAT II 50 Ω 5Vrms, 10Vpk
CH
1
CH
2
CH
3
CH
4
CH
5
CH
6
CH
8
Probe Power Supply
When using the differential probe from Yokogawa (model 701920 or 701922), use the
probe power supply (PROBE POWER) located on the rear panel of the instrument.
For more information about the probe power supply, see “When Using the FET Probe,
Current Probe, or Differential Probe” in section 3.4, “Connecting the Probe” in the
DL7440/DL7480 User’s Manual (IM701450-01E) .
Precautions to Be Taken When Connecting a Probe
• To activate triggers using the CAN Bus signal, apply the CAN Bus signal to the CH1
input terminal.
• When connecting a probe to the instrument for the first time, perform phase correction
of the probe as described in section 3.5, “Compensating the Probe (Phase
Correction)” in the DL7440/DL7480 User’s Manual (IM701450-01E) . Failure to do so
will cause unstable gain across different frequencies, thereby preventing correct
measurement. Calibration must be performed for each channel to which the probe
will be connected.
• Note that if the object being measured is directly connected to the instrument without
using a probe, correct measurements may not be possible due to the loading effect.
Note
Data analysis and data search can be performed on the CAN Bus signals applied to CH3.
For details, see section 2.5, “Analyzing/Searching Data.”