LABVIEW communication with experimental instrument (Ethernet port)

[ChrisNo7]

Hello,

can i please consult if anyone encounters the problem of estalishing the communication between LABVIEW and experimental instrument ?  

My device is a volume pressure controller (VPC, e.g. Wille pump), and we try to link it to the PC end for instrument control and data monitoring, but it cannot be recognised by the PC end (the developed Labview driver), and neither on NI-MAX, not sure if there is anything additional to be installed or configured while using LABVIEW for such purpose ?

Many thanks,

Kui

[wiebe@CARYA]

Ethernet devices are not plug and play. They don't usually show up in Max.

Try ping the device. If you can't, something's wrong with your network setup.

Try (temporarily) disabling the firewall... LabVIEw might not get through. 

Without a lot more details, the only advice left is that something must be wrong.

[Kyle97330]

Perhaps to expand on what wiebe said, any Ethernet devices you have seen in MAX before are either NI ethernet devices such as a Compact DAQ, or they are regular test devices that use the LXI-11 communications standard, and in both cases where they show up automatically the network setup has to have them on a local subnet that it can find them via discovery.

Other Ethernet devices can of course be used but won't show up in MAX automatically... you have to either add them manually or address them directly from your program and not even put them in MAX.  Starting with a ping is good, though I have run across the occasional instrument that won't respond to ping but will still connect otherwise.  What you really need to get started is to know the IP address and port number of the device, and the communications protocol it uses (for instance, does it use Telnet, MODBUS, Ethernet/IP, HTTP, etc.).

Hopefully you have some way of knowing what these things are via documentation... 

[ChrisNo17]

Thank you, I actually tried Ping on the command box, but still not quite right, probably I should ask for the right IP address and Port number from the Device supplier ? or I can create a new one from my side ?

[ChrisNo17]

Hello, actually I also tried the diffrent ways as indicated from the NI webs, e.g. ping using 'cmd' , but it seems probably I should ask for the right IP address and Port number from the Device supplier ?

and the instrument supplier said the communication for their device can be estalished using the ASCII way from the Ethernet port, and they said it need two additional addresses part from the PC one.

not sure is it really that complicated to use LABVIEW to do intrument control in this way ?

many thanks

[billko]

I thought this was an "experimental" instrument.  If this is actually a COTS (Commercial Off-The-Shelf) item, they must have a manual lying around...

[rolfk]

And while many instruments come with a default network setting, quite often to use DHCP in which case the device will either receive a network address from your local DHCP server and in lack of that an address from the auto address network range 169.254.x.x.

Because the address is not fixed you have typically two possible ways to find out about an instrument address.

1) If the instrument has some form of display and keys it will normally offer a method to configure the IP address through this.

2) There is often a manufacturer provided tool that tries to find the device on the network with a proprietary broadcast protocol. This only can work if the device is connected directly to the same network and has an address that is compatible with your computers address. Many of these tools can see the device if it has assigned an auto address because there was no DHCP server available but they can’t communicate with the device to change its address if your computer isn’t in the same subnet. That’s a limitation of the TCP/IP protocol and can’t easily be worked around

3) If your device is pretty old it may also use more obscure methods like bootp and similar. The manual of your device will need to explain in detail how that works but it is involved and requires command line magic and modifications on your computers network tables that are generality only possible with Admin privileges.

[ChrisNo17]

Thanks Bill, yeah they supplier should have provided the instruction manual on it; although not really

[ChrisNo17]

Many thanks !

The pump device is a new version ,according to the supplier; and uses Siemens system. 

Here are what the technician of the supplier said: 

"

You will need a clean installation of LabVIEW, but instrument drivers are not necessary, as Your computer will communicate with the device over the network (TCP/IP) and this is a pure system issue.

actually, we need three IP-adresses.

• One for Your PC, and You already have it.
• Second for the display and third for the device in a network segment You can access from Your computer.

Connecting the device directly to the computer is not possible.

Basically, we have two problems to solve:

• Connection of Your VPC-Controller to the internet with two IP-Addresses (one for the display capable to control multiple devices) and one for the servo-device controlling the piston movement and pressure in the VPC.
• Bind the LabVIEW driver of the VPC to Your existing software infrastructure in LabVIEW controlling the rest of the experimental procedure.

"

[ChrisNo17]

so I have tried to get two additional IP addresses, although not sure how to assign them to the device and control end;

literally their manual said nothing but pressing button...

more suggestions here would be appreciated !