FINS and Visual C++

[cpzao 0]

hi there!, i'm quite new into the PLC world and recently I was given the task of communicating a PC and a PLC via ethernet. After reading here and there, I bumped into FINS protocol, which I dare to say it suits my purposes. I tried the VB programs in the download area and i managed to connect to a PLC and enable outputs and read inputs successfully but I would like to work with C++. Is there any code or software available developed in C++ which allow to communicate a PC with a PLC via UDP/ethernet? Thanks in advance Carlos Edited 11 Dec 2008 by cpzao

[moosty 0]

Hi, I have developed an ActiveX controller for Fins over Ethernet. It is still downloadable from : http://code.google.com/p/indafins/downloads/list with a draft documentation and sample application code. I have never tried it with C++, however it should work without any problem with any programming environment supporting ActiveX. It also works with power point and excel. I am planning to publish an updated version for next weeks, you can get information from: http://indanotes.blogspot.com/2008/11/inda...n-fins-ocx.html

[cpzao 0]

hello moosty, thanks for your help! Either way, I was advised to build my own code for this so... here I go :) Once again, thanks! Carlos

[nguyenthucuc 2]

I have a question: I'm doing the communication between PLC's OmRon and PC. But, with form data send which PC send to PLC has "*" "CR". I don't know what it's, because I see it converter to HEX is "2A0D" but I want it's ACSII code. So, what do I have to? and how do I do? Thanks a lot !

[Berti Baker 7]

Hiya, Isn't 2A hex the code for the * character anyway (i.e. ASCII 42) and 0D hex the "Carriage Return" or CR character (i.e. ASCII 13) checkout Ascii table Regards, Bertie

[nguyenthucuc 2]

Thanks you very much. who did write communication PLC and PC by Visual Basic? Can you help me, please? can you send or upload a simple example?

[moosty 0]

I think you are using Host Link communications. I am attaching a sample software for host link, you can use ReadDM function for reading and WriteDM for writing into data memories. I always use mdlPLC for RS232 communication in my projects and works witohut any problem. However, I have built this sotware this morning for you and did not tried on a real PC. Comm port and communicatino settings were done in Form.Load event, you may need to change them according to your PC and PLC. By default, I have set them to com 1, 9600, e,7,2, no handshake. If you want to see how packages are prepared before being sent to PLC, you can digg functions ReadDM and WriteDM, find the lines objComm.Output = Command you can place a new textbox on form and add something like: frmMain.Text1.Text = Command before lines objComm.Output = Command Hope this helps Sample_Read.zip

[nguyenthucuc 2]

Thanks a a lot "moosty" . this is program which you wrote in above. you used what connecte PLC with PC? Is the cable or ethernet? can you speak clearly for me, please? PS:/ ReadDM command I think in INDAFINS, am not I? Edited 8 Jan 2009 by nguyenthucuc

[moosty 0]

You are welcome. I had developed the module 'mdlPLC' in the attached application for Host Link protocol and it is used for RS232 communication. It has been working on several applications since 2004 without any problem. Host Link is easy to implement, but allows only 4 digits (up to DM9999) of address range, and a data package can contain at most 28 data words. FINS protocol over Ethernet is much more suitable if you deal with high amount of data and it supports data memories over DM9999. FINS protocol is also available on RS232 with just an addition of checksum as in Host Link. For that reason, I believe that Host Link is obsolete and decided to develop INDAFINS for FINS protocol. I have implemented the alpha version for Ethernet only, but I want to add support for RS232 soon. ReadDM function does same operations for both applications, but uses different communication protocols because I wanted INDAFINS to be backward compatible with my existing applications. One of the reasons that I keep ReadDM function as -nearly same- because it returns the data from PLC, making it possible to work on while debugging your application. I hope I can complete the RS232 support for INDAFINS soon.

[nguyenthucuc 2]

thank you very much. I'm going to try it. I want a question, in your example: DATA include ICF, RSV,GCT,DNA,DA1,DA2,...doesn't it? Thus len(data) will greater 28. with your helping, I will develop to complete my project. You are a charitable.

[moosty 0]

Host Link protocol does not include ICF, RSV.. flags. So my example does not contain any of those flags. However, if you want to study on FINS protocol, I am attaching mdlFINS, which is the hearth of INDAFINS. Check the 'PackFinsRead_' function, it prepares the FINS package with ICF, RSV,GCT,DNA,DA1,DA2,... If you are going to use Ethernet communications, the package prepared by PackFinsRead_ function would be enough for you, but if you are going to communicate over RS232, you have to add checksum and '*' character at the end of prepared package, it should be same as in Host link sample I think. Hope this helps for your project. mdlFINS.zip Edited 9 Jan 2009 by moosty

[nguyenthucuc 2]

I also trouble you. But, I test your program which you uploaded by short circuit 2 and 3 dip(RS232). It's usually to appear "ErH" that mean the first character differ "@" PS:/ function getportData, I can change by code below, can't I? code: n = Len(command) For i = 1 To n MSComm1.Output = Mid(command, i, 1) Next I thank you very much to "moosty" because of your enthusiasm helping. Edited 9 Jan 2009 by nguyenthucuc

[moosty 0]

Sure you can, but it does not make any sense actually, PC CPU is so fast that For..Next loop should be executed so quickly and PC collects the output string in com ports output buffer.

[nguyenthucuc 2]

The first next week, I'm going to test with PLC. I hope I'll success with it. I will contact with you again. can you chat with me by nickname? I think I can have better your helping and no waste time than this rely. thank you very much, "moosty"?

[moosty 0]

Sure, I can help you If I am online. I put two Skype buttons on my blog, one adds me as a Skype contact and the other one shows my online status and starts a chat session if I am online. My Skype account name is indanotes.blogspot.com

[nguyenthucuc 2]

Thank you. Nice to be acquainted you