Hioki RM3542-50, Instruction Manual

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8.5 Q&A Regarding External Control
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8.5 Q&A Regarding External Control
Common Questions Answers
How do I connect external trigger input?
Short-circuit the TRIG input pin to an ISO_COM pin using a switch or
open-collector output.
Which pins are common ground for
input and output signals?
The ISO_COM pins.
Are the common (signal ground) pins
shared by both inputs and outputs?
Both common ground pins can be shared by inputs and outputs.
To confirm output signals
Confirm voltage waveforms with an oscilloscope. To do this, pull up
(through several kO) the output pins, such as the EOM and comparator
judgment outputs, to the power supply and check the voltage.
I cannot input the (control) properly.
How can I confirm it?
For example, if triggering does not operate properly, bypass the PLC and
short the TRIG signal directly to an ISO_COM pin.
Be careful to avoid power shorts.
Is the comparator judgment signal (HI,
IN, LO) retained during measurement
(or is it turned OFF)
The state is determined at the end of measurement, and is off once at the
start of measurement.
Why would the EOM signal not be
detected?
Try using the Pulse setting for the EOM output.
When the measurement time is short and the EOM output is set to Hold,
the time to de-assert may be too short to be detected by the PLC.
When the EOM output is set to Pulse, after the completion of EOM, the
signal is asserted (ON) for the specified pulse width and then turned
(OFF), therefore the EOM signal can be detected by the PLC even if the
time to de-assert is too short.
What situations cause measurement
faults to occur?
An error is displayed in the following cases:
•
A probe is not connected.
•
A contact is unstable.
•
A probe or measuring object is dirty or covered by an oxide layer.
•
Measuring object resistance is much higher than the measurement
range.
Is a connector or flat cable for connec-
tion provided?
A solder-type connector is supplied. The cable must be prepared at the
user's side.
Is direct connection to a PLC possible?
Direct connection is supported for relay or open-collector outputs and
positive-ground optocoupler inputs. (Before connecting, confirm that volt-
age and current ratings will not be exceeded.)
Is it possible to use the communication
of RS-232C and the EXT. I/O control
simultaneously?
After setting up measurement conditions with the communications inter-
face, it is possible to control measurement with the TRIG signal while
acquiring measurement data via a communications interface.
How should external power be con-
nected?
The instrument's EXT. I/O input and output signals all operate from an
internal, isolated power source. Therefore, power must not be supplied
from the PLC side (prohibited).
I want to acquire a measurement value
using the foot switch while free-running.
The software for acquiring measurement values is available for download
from our website for free. Please use the software.