Communications Protocol for FieldPoint FP-1601

[JonathanC]

Hi,

I am hoping to read current values of input channels on an FP-1601 by communicating with it directly - i.e. without using OPC, LabView, etc.  Can anyone provide details on the ethernet protocol used to communicate with the FP-1601?  I don't need to know the entire protocol (configuration, etc.) but I do need to know what is needed to read input channels.

Thanks,

Jonathan

[Nadim R]

Hi Jonathan,

What do you mean by communicate directly?  What type of program do you want to use to send ethernet commands to your FP-1601?  You can connect your FP device directly up to your ethernet card by following this KB.   I hope this helps.


Regards,

Nadim
Applications Engineering
National Instruments

[JonathanC]

Your KB post describes the connection needed at the physical layer.  I am asking about the protocol that Fieldpoint software (on a PC) uses to communicate with the FP-1601.  In other words, what sequence of bytes do I need to transmit to the FP-1601 to read the current value of an input channel, and how should I interpret the response?

Jonathan

[TommyTestBoy]

Jonathan -

FieldPoint uses a proprietary protocol over Ethernet.  You will need to use the FieldPoint API provided in LabVIEW or CVI, or you will need to use OPC.  If you have a cFP-1804 or cFP-1808, then you can use Modbus TCP to get I/O from the FieldPoint HW, or if you are willing to use the serial interface of the cFP-180x, then you can use the FieldPoint Optomux serial protocol.

Hope this helps.

-Tommy

[reddogger]

Jonathan,

What was the final resolution of this issue? I have a similar problem where I want to read analog values from a cFP device from inside a Windows program that I am writing.

- Jim

Message Edited by reddogger on 02-08-2007 09:31 AM

[JonathanC]

I looked into it a bit further and even tried sniffing the protocol with WinDump.  The protocol is called Logos, and it is proprietary to NI.  NI, if you're listening, it certainly would be helpful if you could publish even a subset of the Logos protocol.  This would improve interoperability with other platforms.

[JonathanC]

If you have cFP then you can use Modbus/TCP - that's an open protocol and it's quite easy to use.  It's the older FP that uses Logos.

[reddogger]

I've got a new cFP-2100 and I'm familiar with Modbus/TCP.

Where's a document/paper that describes the Modbus register layout in the cFP?

[TommyTestBoy]

To be clear, only the cFP-180x Network/Serial interfaces natively support Modbus.  The Real Time controllers ([c]FP-2xx0 models - both traditional and compact FieldPoint sytles) do not support the Modbus protocol.  You could write a Modbus server in G that runs on the embedded controller and then you could do the mapping yourself - or you can devise your own protocol to get dat from the RT controller to your host application.  But you will not be able to use Modbus with your cFP-2100 controller out of the box.

-Tommy

[Twerkinstein]

I know this post is terribly old, but I'm trying to do a similar task: I have a cFP-2120 that I would l like to read values from using Simulink. I think this is possible, but I'm not sure. From what I gather, here are some avenues I'm thinking of chasing down: 

1. Using an OPC server and the Industrial Communications Toolbox in simulink to set up communication

2. Writing a MODBUS server to run on the embedded controller that will then communicate with Simulink via MODBUS

3. Figuring out if the serial communication is done with some easy-to-work-with protocol and using Simulink to decipher it

Do you know if any of these seems like a good option right off the bat or is there something else that's more straight forward that you'd recommend?

Thanks!

   James