Hello everybody
I am sorry for my english, but i hope you will understand what i am talking about.
I want to read and write data from PLC (quantum) to a computer using dll library mbplus.dll,
like i can do it with libnodave.dll in Siemens s300 or s400 PLC. It is starnge but i can find no information about doing this with modicon, while i found a lot of information for the siemens!
The one of the problems is, that i am not only bad in english, but i am bad in programming too.
So i need a programming example how to program my aplication. If anybody can help me with this i will be very thankful!
A few month earlier i programmed ADVANTECH PCL-722 card(this is 144 digital IO) in the same way(using examples and dll library) and i had no problems with it.
Please dont tell me about OPC client and OPC server
Thank you!

priviet Igor,

To helping you I need more info.

Which kind of PLC Quantum: Programmable with Unity or Concept or Modsoft ??

The model of Quantum is..?

Why you need to use Modbus Plus??

Easier is to communicate in modbus RTU with thousands of programs

I don't know MBPLUS.dll but it seems to be an old driver... is it ??

Which software are you running in the PC station?? Do you need to represent the data read from PLC in an overview system in the PC?? Or simply transfer them in a database?

SO in the end describe your PLC configuration and what precisely you need from it.

Well. Ok. The PLC i do use, is quantum (CPU 434 12A) and (416NHM30030) PC card to communicate with it.
The main progect is written in Concept 2.6 XL EN. The program is written in FBD language.
Why mb+? That is because of the 416NHM30030 card is already installed in PC, and the distance between PLC and PC is more then RTU can provide(It is 20 metres).
I need to represent information that i wish to read from PLC in the PC, and write that information to database.
As for me MBPLUS.dll is very old, but i can not find another that is younger
Well! What is it for?
Not so long ago mine Siemens ASi module was broken and there was no other to substitute with. So there was an idea to make a bridge PROFIBUS vs. MB+ to provide the broken sistem with necessary amount of Digital IO. I can read and write data from s400 to PC using libnodave and Visual basic but i can not read or write data from quantum that way I know that is possible to do without any SCADA or OPC. Have an idea?

I don't understand if you are still using S7 400 or not...



I still don't understand why MB+ and why a bridge. Do you want the QUANTUM to communicate with S7400?
And so the S7400 will communicate with the PC (VB application)..

Anyway in my opinion is to choose always the easier way...

so you might use the serial port RS232 (you have two port Modbus and one modbus plus) of QUANTUM that is MODBUS RTU and connect two converters rs232<-->rs485 (so you may reach more than 400m). One converter connected to the CPU the other one to the serial port COM1 of the PC.

Using a VB application I think is very easy to read and write variable in standard modbus RTU. You may find in internet a lot of samples.

You might test the modbus link with Modscan software that you can download from internet.

Thank you aggattapauer, for your advice!

I do understand what are you written about
I have a lot of free time to learn C or C++, but i have no possibility to purchase two converters RS485<-->RS232...

Any way the problem still remains the same:
-read data from S400 using VB or C or C++ or another programming language.
-write data to quantum (434 12A) using VB or C or C++ or another programming language.
-read data from quantum (434 12A) using VB or C or C++ or another programming language.
-write data to S400 using VB or C or C++ or another programming language.

The way it should be done: is to use NO OPC servers or other SCADA. Only libraries are permitted
Any kind of libraries...
Thank you!

See www.automatedsolutions.com/products/modbusplus.asp

Hello. I am here again, just to say, that i have solved my little problem.
The software i use:
- Concept 2.6 XL EN
- MBX Driver Suite Version 4.20 for Windows® NT/9x
- Visual Studio Net 2003
- Modbus Plus DOS driver for SA85 adapter (http://www.download.schneider-electric.com/C1257307002C03A4/All/852566B70073220C85256969006ECA9C/$File/043510798%20mbplus%20dos%20drvr.zip) this is the examples of the sourse files in C language. They are rather old and will not help you to write 32-bit application, only for 16-bit applications.
- Borland C 5.01 for compiling 16-bit source files from Modbus Plus DOS driver for SA85 adapter.
- 32-bit Netlib.lib library for compiling application with a 32-bit C compiler.
I did not managed to get "The 32-bit Modbus Plus Software Development Kit (SDK)". It is available from www.cyberlogic.com for 1000$.
The main problem for me was to obtain a 32-bit Netlib.lib Netlib.h and netbios.h. I found them in "MBX Driver Suite Version 4.20 for Windows® NT/9x". They are placed in ...\MB+\4.20\Legacy\v2xx\WinNT\Lnetlib\DEMO\ and looked like NETLIB.LI_ NETLIB.H_ NETBIOS.H_. All you have to do, to obtain normal files, is to expand them.
So, now i cat READ and WRITE holding registers, input and output coils from PC to PLC using my own application spending no money for obtaining OPC SERVERS, Modbus Plus ActiveX Controls or SCADA.
Additional information can be found in:
- IBMHost.pdf
- WINNT.pdf

If you have questions- ask me here, or send me eMail.