Hioki ST4030, Instruction Manual

Page: 220 / 256

212
Troubleshooting
External controls (EXT.I/O)
Symptom Check item or cause Corrective action and reference page
All operations are disabled Is the wiring correct? When wiring is incorrect, check the EXT. I/O
again.
• Connector is disconnected
• Are the pin numbers incorrect?
• ISO_COM terminal wiring
• NPN/PNP settings
• Contact (or open collector) control (not
voltage control)
• Power supply to external devices (Power
supply to the instrument is not required)
See: “10 External Control (EXT. I/O)”
(p. 133)
Deliberate movements are
disabled
Do the I/O pin connections
match?
Test and check the I/O pin operations.
Reference: “EXT. I/O test” (p. 131)
Do the I/O signal control
timings match?
Check the I/O signal control timings using the
timing chart.
Reference: “10.4 Timing Chart” (p. 142)
Cannot change the settings
table
Is the table to which you
want to switch enabled?
Check the status of the table to which you
want to switch using the table settings window.
Reference: “3 Switching Test Conditions
(Table Functions)” (p. 25)
FAQ regarding external control (EXT. I/O)
Question Explanation/Method
How best to connect to START
signal inputs?
Short (turn on) the START terminals and ISO_COM terminals using
switches and open collector outputs.
Which is the input signal common
and the output signal common?
It is the ISO_COM terminal.
Is the common terminal shared
for both inputs and outputs?
Use ISO_COM terminal for the common terminal for both the input and
output signals.
Check that output signals are
being output.
Check the voltage waveform using an oscilloscope. At the same time,
pull up the EOM signals (several k
Ω
) to the instrument isolation voltage
outputs (ISO_5V) and check the voltage level.
Input (control) is not performing
properly, but what checks should
I make?
For example, if the START signal does not work effectively, try shorting
the TRIG terminal directly to the ISO_COM terminal instead of controlling
using the programmable controller. Be very careful of short circuits to the
power supply.
Is the judgment results signal
also held during measuring? (Or
does it sometimes turn OFF?)
The judgment results are deleted when measuring starts.
Can I connect to the
programmable controller directly?
You can connect directly if the programmable controller output circuit is
compatible with a relay or open collector, or the programmable controller
input circuit is compatible with contact inputs. (Before connecting, check
that the voltage level and flow current do not exceed the ratings)
Can I use communications such
as RS-232C and an external I/O
control simultaneously?
Yes, you can.
Example: Set the measuring conditions using communications, and
measure using EXT. I/O START signals.
How should I connect the
external power supply?
The I/O signals for the instrument external control terminal (EXT. I/
O) operates using the isolated power supply in the instrument.
Consequently, it is not necessary to supply power from the
programmable controller. (ISO_5V terminal inputs are prohibited.)