Toshiba SX 2000 - Manual (Page 177)

6.7 Troubles due to external factors
When a problem with the S2T system occurs as one of the following phenomena,
external factors should be suspected.
(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 that 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 neceessary
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.
Apart from the above causes, if, for instance, the ambient temperature exceeds the
specified range, stable operation of the system cannot be guaranteed. Take thorough
precautions over the environmental conditions.
Chapt.6 Troubleshooting
160
Sequence Controller S2T