Sensors/Actuators communication to a single laptop

[efer2109]

Hello everybody, 

I'm a student in mechanical engineering, working on a project regarding the realization of a drop-weight impact test machine. One of the tasks is to create the proper software architecture to acquire data from the sensors and to drive the actuators.

My aim is to create a sort of plug-n-play hardware network (I don't know if I'm using the right definitions) that can directly interface with a laptop in a easy way, ex. via Ethernet.

I'm completely new to the world of LabVIEW and I don't have a big experience in signal processing, actually I'm studying the characteristics of the sensors at my disposal.

For example to measure distances I will use two laser sensors of the M7LL series, produced by MEL (you can find the manual as attachment). This type of sensors has an electronic system with integrated Ethernet interface, and a D-sub 25 plug for data and power supply.

My questions are, how can I create a communication between this sensor and a VI on my laptop? The in-out data through the D-sub are simply a copy of the data through the Ethernet, right? If it is so, can I use the D-sub only for power supply? Do I need any further hardware to use this sensor with LabVIEW? To conclude, how can I route data coming from different sensors (both from hardware and software point of view) in order to be able to connect all of them to a single ethernet port of the PC?

Thank you in advance for your patience and for your time

Edoardo

[Albert.Geven]

As I look at it, you can do everything with Ethernet if the speed is not a problem.

Each packet is 860 bytes and that is quite a lot for simple distance data so you need to calculate if 10 Mbit and a lot of overhead is fast enough to read out at speed.

Any way with a simple ADC card you can also read out analog data if you want.

On Ethernet you need to distinguish on the ethernet address, so you set them each on their own address.

Inside your software you set them up for continuous data and start reading both incoming streams.

I would start with one and check if timing is sufficient and then add the other one.

Good luck

[efer2109]

Shouldn't be the Ethernet speed about 100 Mbit? Am I wrong?

So if I understood correctly, you think that to use the analog D-sub exit should guarantee faster acquisition, right?

But in any case I would then use Ethernet to create the interface for the pc, do you think it is the same as starting directly from the sensor with the Ethernet? 

Do you think that a single ADC card can be suitable for my needs to route signals from different sensors?

Sorry for the amount of questions and thank you for you time

[Albert.Geven]

I'm not promising faster acquisition but maybe easier.

NI cards easily get 200k points per sec and for two channels you get 100k.

It is not very cheap but working a few days on interpreting ethernet data is also costly.

Maybe someone has a card lying around.