Hitachi NJI-350B - Manual (Page 280)

Chapter 13 Troubleshooting
13-5
13.2 Checklist when Abnormality Occurred
If an error occurs in the MICRO-EH system, check the following items. If there are no problems in the following items,
contact our service department.
(a) Power supply related items
• Is the power voltage correct? (85 to 264 V AC)
• Are there any warps in the power supply waveform?
• Are there any excessive noises in the power supply?
• Is power supplied for all basic and expansion units?
(b) CPU related items
• Are the initial settings (CPU initialization, I/O assignment, parameter settings, etc.) proper?
• Are there any error codes that are output to the special internal output?
• Is the RUN switch (or RUN terminal) in the proper location?
• Are batteries mounted properly? Is the battery life still remaining? (23/28-point types only)
(c) Input module related items
• Is the input voltage within the specifications for the internal section?
• Is there any noise or chattering in the input?
• Do the I/O assignment numbers in the program match?
• Is the wiring done properly?
(d) Output module related items
• Do the module and the load power supply type (DC/AC) match?
• Do the load voltage and current match the specification of the output section?
• Is there any noise or chattering in the output waveform?
• Is the wiring done properly?
• Do the I/O assignment numbers in the program match?
• Are there any unintentional overlaps in the output numbers?
(e) Wiring related items
• Is the wiring between the expansions mixed up with other wires?
• Are the power supply wiring and I/O cables separated?
• Are there any foreign substances in the connector of the basic/expansion units?
Cautions
(a) When returning the unit for repair, please notify us of the malfunctioning conditions in as much detail as possible
(including error codes, malfunctioning I/O bit number, will not turn on or off, etc.).
(b) The tools and devices necessary for troubleshooting are briefly as follows:
Phillips/flathead drivers, digital multimeter, tester, oscilloscope (necessary depending on the case) etc.