Data Logging

A D.G. is?

Does the engine starting unit have the data you're looking for, accessible at an output port?

If so, what comm protocol does the output port use?

Is the comm protocol and internal data documented by this manufacturer?

Or do you need to have sensors to for the pressure, temperatures and etc.? (I've been developing an etc. sensor for years now, but it's not market ready yet).

What are you going to do with the data once you have it?

Have you tried to contact National Instruments ? They have many products, some of which may be what you need.Good luck.

Basically i want to find out the efficiency of DG (diesel generator) set at various loads and hence i want to do data logging of the same.

The engine starting unit has one input port (which acquires data from various sensors which are already supplied along with the DG). The signals from the sensor are 4-20 mA dc. The authorized service engineer says that the signals are available at output port (9 pin) but the company is unable to provide adapter for the port since the engine starting unit is an imported one and the adapter does not come in the standard spares.

I am having a NI data logger. There are no problems with data logger but the problem is basically of data acquisition from the output port.

How will you know which pin is which signal even if you get an adapter cable? Are there 8 signals common grounded or 4 signals, each with a (+) and (-)? Which is which?

How will you know what the data is scaled? What is 4mA? what is 20mA?

9 pin output port suggests to me that you may be dealing with digitized output. The best way to determine the pin-out, and the sort of data (analog or digital) being output, is with an oscilloscope. The first task is to determine the signal ground, or common (which most likely will be pin 1 or the connector shell). Once you know that, you can have a look at each pin with the scope to determine what signal is being produced. That gives you the information you need to set up your NI data logger. After that, you will need to figure out how the various signals correlate to the actual measurement parameters...

Look at some of the HVAC data loggers. They capture pressure, temp, etc. HOBO by Onset may have what you want.