Does MODBUS RTU Support for Windows


Thread Starter



I want to Develop a project in Visual Basic 6.0 with communication protocol MODBUS - RTU. i want to develop a 128 error Annunciation System. so thats i want to use MODBUS RTU. why MODBUS ASCII is better than MODBUS RTU? & this project i want to run on Windows, my senior told me that MODBUS RTU can't support Windods, is it true? So please tell me What communication Protocol Should i use for better communication.

Thanking you

Yes, you can communicate to MODBUS RTU device in Windows2K/XP.

If your VB project, include MSCOMM.MSCOMM is an activeX that controls the serial port of the computer. All you have to do is to suply properly the baud rate, parity, etc. to the MSCCOMM. Please don't forget to attach CRC in the message you are going to send.
You can use either reliably in Windows.

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Raymundo D. Balderas

The most used serial protocol is Modbus RTU. Modbus ASCII in not better that RTU they both are a good option, depending on the application. Modbus RTU is no dependable on Windows OS or other operating system. You could Develop your VB project with no fear. There are several Modbus RTU commercial options into the market place developed for windows OS.

Just define, if your VB project will me a master device or a slave device.

Hope this helps.

Raymundo D. Balderas
Mexico D.F.

Lynn A Linse

Windows can handle Modbus/RTU - however it can be challenging depending on the other products you must talk to. As a Master, you'd have no trouble polling Modbus/RTU slaves with either sloppy or tight timing designs. As a Slave, you could maybe have trouble responding to a Master who was being overly-legal in the timing arena, however most Masters are sloppy timing to handle a wider range of slaves.

You will find supporting Modbus/ASCII a problems as not all 3rd party products support Modbus/ASCII. Many small, low-cost slave devices will be Modbus/RTU only. Plus Modbus/ASCII cuts your performance in half always - you must send twice as many bytes to accomplish the same thing.

If this is just a toy or demo or school project, then Modbus/ASCII is fine. If you are creating a serious product with a future, then you need to use Modbus/RTU eventually.

best regards
- LynnL:,

Milind D. Kulkarni

Hello ,

Thanks for u r valuable suggestion for me , now am going to Develop s/w in Visual Basic 6.0 using MODBUS RTU on Windows 98 . Before build the Electronics Device , I want to test that program on other PC (PC to PC Communication) so please tell me from where I can download Visual Basic Program who support PC to PC Communication in Visual Basic 6.0

Thanking You.

Milind D. Kulkarni