Toshiba TR PMIU, User Manual, Page: 37 / 182

27
PMIU unit
・ LED status
PMIU unit has POWER LED in top left of case. If it is blinking, there may be some error. There are 2 cases,
communication error and RUN-force mode.
・ Operation mode
Connect PC to PMIU unit and check operation mode of PMIU. If PMIU mode is RUN-F mode, unit
operates normally even if Expansion I/O unit attached to PMIU unit is different from project, and the I/O
status of Expansion I/O unit is not updated.
Input
・ Input signal status
Check signals at the terminal of Expansion I/O unit. If the screw of signal terminal is loosen, the signal
may repeat unstable chattering. And, the core wire which came loose may short-circuit with the next
terminal.
If input signal is OK, unit may be faulty. Replace the unit with new one.
・ Usage of input device/register
Connect PC and monitor the input register/device in RUN mode. If the monitored device is changed
corresponding to the external signal, the cause might be in the project.
Check usage of the device/register in project. Note that unit is operation normally in RUN-F mode even
if Expansion I/O unit is mismatch.
Output
・ Output status of unit
Output changes according to the execution of the program. If no, check IO allocation and usage of the
device/register in project. Note that unit is operation normally in RUN-F mode even if Expansion I/O unit
is mismatch.
The core wire which came loose may short-circuit with the next terminal.
・ External device connected to output
If I/O of unit is operates normally, check input specification of external devices connected to the unit.
Environmental factors
Troubles may caused by severe electromagnetic noise, difference of grounding potentials between unit and
external circuit, mechanical shock/vibration, high/low temperature, dewfall, oil mist, water drop, dust, etc.
Only when appropriately set up in the panel that endures water, front side of unit endures a weak spray of water.
However, a strong jet flow cannot be endured. The material of the front seat cannot endures some kind of oil,
chemicals etc. Note that back of unit has no protection.
Moreover these factors shorten the life of the unit. Avoid these factors or give measures at installation.
Noise might enter to unit via wires. Isolation of I/O signal, or earth line may lead to the stable operation in some