Toshiba Programmable Controller PROSEC T3 - Manual (Page 88)

6. Troubleshooting
6.7
Troubles due to
external factors
If one of the following abnormalities occurs in the system, check
possible external factors.
(1) If an abnormality occurs synchronously with the operation of I/O
equipment:
The noise caused at ON/OFF of the output equipment may be
the source of the abnormality. Take necessary measures
mentioned in Section 3 Precautions for I/O modules.
(2) If an abnormality occurs synchronously with the operation of
surrounding equipment or high-frequency equipment:
The noise induced on I/O signal lines may be the source of the
abnormality. The surge voltage, voltage fluctuations, or
differences of grounding potentials may have caused the
abnormality, depending on the power supply system or the
grounding system.
Check the abnormality in accordance with the precautions in
Section 4 Installation and Wiring. For some cases, isolation
from the ground may lead to the stable operation.
(3) If an abnormality occurs synchronously with the operation of
machinery:
The vibration of the equipment may have caused the
abnormality.
Check that the installation status of the units and modules and
take necessary measures, including the use of vibration-proof
installation.
(4) If a similar failure is repeated after the module is replaced:
Check that no metal debris or water drops have been entered
into the unit/module.
Apart from the above points, consider environmental conditions,
if the ambient temperature is beyond the specified range, stable
operation of the system is not guaranteed.
80 PROSEC T3