To prevent these some dangerous situations in advance, it is always important to check the condition of ship's machinery.
Using external equipment for monitoring to check the condition of engine of ship's pivot, because ships haven't the equipment for monitoring internally.
Currently in ship, check the pressure of each cylinder using mechanical or digital pressure gauges for catching something wrong of cylinder, piston, fuel pump and etc.
Mechanical method is connecting mechanical pressure gauge to indicator-cock for checking the pressure of cylinder.
This method have instrumental error that caused by gauge's needle and is impossible to analysis and collect data promptly. So, it is changing to digital method.
Digital method have low limitations and can indicate the data to LCD promptly by using digital pressure gauge and LCD.
But, this method have a demerit that caused by using data cable for TDC and BDC and RPM from flywheel.
This paper decribed that send some signal from encoder attached to crankshaft of marine-engine to measuring instrument using power line modem(PLM) and display cylinder pressure, rpm, etc. on LCD.
To existing pulse signal occurred from encoder is transmited through wire to directly, but this way take very much time for measure work because bracket which attached encoder is very far distance to ship main engine's top floor.
Power line modem small installation cost because use power line that is established in existing just as it is, and value is thought to be as goods that can very prefer on the spot because modus operandi is very simple.
Experimental works using the proposed method confirmed that pressure waveform and the engine rpm are good in each cylinder whenever send-receive signal of compression beginning point pulse of each piston by PLM is transmitted.