Hioki MEMORY HiCORDER 8855, Instruction Manual

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2.5 Logic Probe Connection
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DANGER
The logic input and 8855 instrument share a common ground.
Therefore, if power is supplied to the measurement object of the
logic probe and to the 8855 from different sources, an electric
shock or damage to the equipment may result.
Even if power is supplied from the same system, if the wiring is
such that a potential difference is present between the grounds,
current will flow through the logic probe so that the measurement
object and 8855 could be damaged. We therefore recommend the
following connection method to avoid this kind of result.
(1) Before connecting the logic probe to the measurement object,
be sure that power is supplied from the same outlet box to the
measurement object and the 8855 using the supplied power
cord.
(2) Before connecting the logic probe to the measurement object,
connect the ground of the measurement object to the 8855
ground terminal. Also in this case, power should be supplied
from the same source. Refer to Section 2.2, "Power Supply and
Ground Connections" for grounding terminal details.
Object to be
measured
8855
Outlet
Power supply
Ground
Figure 1
8855
Function ground terminal
GND
Figure 2
Object to be
measured
In this case too, obtain power
from the same supply.
NOTE
2.5 Logic Probe Connection
The logic input is located on the rear of the
instrument. Up to four probes can be connected.
Since one logic probe can record 4 channels, the
combined maximum recording capability for logic
waveforms is 16 channels.
Connect the probe by aligning the groove on the plug
with the ridge on the connector.
If no logic probe is connected, the corresponding logic waveform is
displayed on the screen at high level.
Carefully read the instruction manual supplied with the probe.
Do not connect logic probes other than supplied by HIOKI to the logic inputs.