Hioki DM7275 Series - X84; Frequently Asked Questions for External Control (EXT I;O); Cleaning

175
Cleaning
FrequentlyAskedQuestionsforExternalControl(EXTI/O)
Question Instruction/Method
What is the required connection to input
TRIGsignal?
Short (ON) the TRIG pin and ISO_COM pin with a switch or open-
collector output.
Which are the common ground pins for
input and output signals?
The ISO_COM pins.
Are the common (signal ground) pins
sharedbybothinputandoutput?
Use ISO_COM pin as the shared common pin for input and output
signals.
Howtocheckwhetherthesignalis
output?
Check voltage waveforms with an oscilloscope. To do this, pull up
(by several k
Ω
) the output pins such as EOM signal and comparator
judgment results signal to the isolated power output (ISO_5V) of the
instrument and conrm the voltage level.
HowdoItroubleshootinput(control)
signal issues?
For example, if TRIG signal does not operate properly, bypass the
Programmable Controller and short the TRIG pin directly to an ISO_
COM pin. Take care not to short-circuit the power supply.
Arethecomparatorjudgment
signals(HI,IN,LO)retainedduring
measurements(orwilltheybeOFF)?
When the state is RUN and the trigger source is set to INTERNAL,
judgment results are retained even during measurements.
In the other cases, judgment results will be cleared once a
measurement has started.
What is the condition to output the ERR
signal?
An error is displayed in the following cases:
• Metal pin of the measurement cable is not in contact.
• The contact is not stable
• Metal pin of the measurement cable or object to be measured is
dirty or has an oxide layer.
• The measurement cables are cut.
• Capacitance of the object to be measured is small.
Is a direct connection to programmable
controller available?
Direct connection is possible if the output circuit of the programmable
controller supports relays or open collectors and the input circuit
of the programmable controller supports contact input. (Before
connecting, conrm that voltage and current ratings will not be
exceeded.)
CanexternalI/Obeusedatthe
same time as RS-232C or other
communication?
Yes.
(Example: Set measurement conditions using communications and
measure with TRIG signal of the EXT I/O.)
Howshouldtheexternalpowerbe
connected?
All the instrument's
EXTI/O
input and output signals operate from an
internal isolated power source. Power need not be supplied from the
programmable controller (supplying power to the ISO_5V terminal is
prohibited).
Can free-running measurement values
be acquired using a foot switch?
Measurement values can be acquired using the sample application.
The sample application can be downloaded from our website (http://
www.hioki.com).
14.2 Cleaning
To clean the instrument and optional equipment, wipe gently with a soft cloth moistened with water
or mild detergent.
Wipe the LCD gently with a soft, dry cloth.
Maintenance and Service
14
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