Modbus string conversion

[Pedjasns]

Hi! I'm a Lookout novice.

I have a self designed MODBUS device where I assigned a range of Holding registers to represent an ASCII string (some name). Each 16bit  register has only one character of that string, in it's lower byte. The higher byte is zero.

How can I assemble and DISPLAY characters from this range of registers into a single field containing desired string (name) as letters not as numbers? I couldn'f find such a conversion function. All I could make so far was to display these characters as numeric.

I am using Lookout 6.0 Trial SW.

Cheers

[Robert_Lee_NIUK]

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Hi Pedjasns

We're currently looking into your issue here at NI UK & Ireland. I have found some previous queries on this subject by other Lookout users and it seems that unfortunately there is no direct conversion tool. This means that in order to perform the conversion, you must therefore perform hardcode implementation. I will continue to look into this for you and hopefully we will be able to come up with some method of performing such a conversion. If possible, it would be of benefit if you could attach your program to a post here. Alternatively, I will send you an email with which you can reply if you would prefer to keep your program off the forums..

Hopefully we can come up with some form of a solution!

Thanks for contacting NI

Best wishes

Rob

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[Pedjasns]

Hi Rob,

Thank you very much for your prompt reply.

I would be interested in hardcoding of that (and other if needed) function, if I knew how to do it. Is there any manual or tutorial on that?

I would also post you the code of my application, but please give me an E-mail where to send it. I wouldn't publish my E-mail address in this forum as yet.

Since I used LabView for years, I choose Lookout as a quick and handy tool for making this demo application. It might be ad-hoc but so far I have a good experince with it.

Regards

[Robert_Lee_NIUK]

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Pedjasns,

I have sent an email to your account. By replying to that email, you can send your code directly to me.

Many thanks

Rob

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[Pedjasns]

Hi Rob,

I am sorry but I cannot find any message from you. Can you please tell me to what account did you send the message to?

Instead, I am giving you some temporary E-mail so you can send it there.

pedjas@nspoint.net

Regards,

Pedjasns

[Robert_Lee_NIUK]

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Pedjasns

Have sent email to that email address. Hope you get it ok.

Many thanks

Rob

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[Robert_Lee_NIUK]

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HI predrag

Thanks for sending the program over, i've had a look at it and I can see what you're trying to do. Unfortunately, myself and my team have been unable to develop any practical hardcode for you to utilise, I was only able to come across some information from a previous Service Request which occurred in the US. The text details some hardcode written by an AE for a customer who was having a similar problem to you. The attached information might hopefully be of use to you, I just apologise that we were unable to develop a full solution. Also, the following links might also be handy.:

http://zone.ni.com/devzone/cda/tut/p/id/3381

http://zone.ni.com/devzone/cda/epd/p/id/835


There is however and alternative. You mentioned in a previous post that you were an experienced LabVIEW user and that you only have an evaluation version of Lookout. It might therefore be of more use if you were to develop your program in LabVIEW which has MODBUS facilities. I have found some very good information on how to develop these kind of applications, just copy the following links in to your browser. The first URL links directly for the MODBUS library installer for LabVIEW version 8.x.


http://sine.ni.com/devzone/cda/epd/p/id/4756

http://digital.ni.com/public.nsf/allkb/64D9902E8B9AE4AF8625712D0076B463

http://zone.ni.com/devzone/cda/tut/p/id/2956

http://zone.ni.com/reference/en-XX/help/370246E-01/lvdschelp/creating_modbus_io_server/


I apologise once more for not being able to give you a full and viable solution, I really hope the information I have provided here can be of use to you.

Best wishes in the continuing development of your programs


Rob

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[Pedjasns]

Hi Rob,

Thank you very much for support anyway.

The application I was trying to develop is just for demonstration purposes, to display functionalities of the software I was developing for a Linux machine. The reason I went for Lookout is "plug and play" SCADA and OPC capability, which suppose to prove the customer that the device I made is MODBUS compliant. If I developed it in LabView it wouldn't be that persuasive.
Anyway, the one I made so far will do. Some nice buttons and lights should be enough for basic MODBUS commands compliance.
However, the feature I was looking for should be included in one of future versions of Lookout, if so many customers are asking about, as well.

Thank you very much for helping me again. Even the word about non existance of the function I was looking for is a great help, since I was thinking that I wasn't doing something right.

Best regards,

Pedjasns

[Robert_Lee_NIUK]

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Pedrag

thanks for the feedback, it's always appreciated. The service request automatically generated by these forum posts are utilised by our R and D engineers for future development. Therefore, this problem may well be encountered and hopefully, rectified.

Many thanks for contacting NI

Best wishes Pedrag

Rob

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