Interfacing AB Micro830 with Computer using generic RS232 cable

[THED]

Hi,

I am working on a University project at the moment. The project scope is to implement a simple PID Program for a process tank and implement a SCADA/ HMI using Allen Bradley Micro830 PLC.

I know AB has its own HMI/ SCADA hardware. However, the aim of the project is to use software only.

So my questions are,

1) is it possible to implement a SCADA/ HMI on the computer with a generic RS232 cable + available SCADA/ HMI software or I need a RS232 cable that specifically made for Micro830?

2) how do I make my Micro830 communicate with the computer via RS232 cable? Are they able to communicate just by having the same modbus code? I am not sure how to do it.

3) how do I go about doing it? What are the available softwares? I thinking of using GE's CIMPLICTY but haven't got around to try it yet.

[Dennis_Knutson]

I'm not sure why you posted your question here. This is for NI hardware and software. If you need the RS-232 connections for an Allan Bradley product, you should check with Allan Bradley. There is no such thing as a 'generic' RS-232 cable anyway.

If you were to choose NI software (LabVIEW, LabVIEW w/DSC, etc.), then post back to the appropriate board. Each software has different options and solutions for communication.

[unclebump]

You are in luck, the serial ports support modbus and modbus tcp on the ethernet connection.

Micro830/Micro850 controllers support the following communication

protocols through the embedded RS-232/485 serial port as well as any installed

serial port plug-in modules:

•

Modbus RTU Master and Slave

•

CIP Serial Server (RS-232 only)

•

ASCII (RS-232 only)

In addition, the embedded Ethernet communication channel allows your

Micro850 controller to be connected to a local area network for various devices

providing 10 Mbps/100 Mbps transfer rate. Micro850 controllers support the

following Ethernet protocols:

•

EtherNet/IP Server

•

Modbus/TCP Server

•

DHCP Client

See this document.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/2080-um002_-en-e.pdf

You can download the NI modbus library for a good start at it.

[THED]

Would the cable that I have work with my controller?

[Dennis_Knutson]

Why do you continue to ask questions about allan-bradley instead of asking allan-bradley?

[THED]

Because I can't get any answer from them

[Dennis_Knutson]

Does that AB cable/adapter even have the DIN connector that you need?

[THED]

Yes it does but I just need someone to confirm that it works with Micro830. AB forum / live chat is not very helpful

[THED]

Ok, lets say the cable works. How do I "bridge" my pc and PLC together? Is the cable going to do the job or the scada software is going to do the job? Or is it the program itself? Can you please enlighten me on this? How do I store and extract data from my plc? Eg, I am recording water level and flow rate. How do I extract it from my pc to put on my pc's screen? I am so new to this.

[unclebump]

The cable does nothing but allow your program to talk with the plc and retrieve information. The modbus protocol allows the pc to issue commands to the plc. The plc then responds back with information. This is done as a master/slave arrangement. The pc program is the master device and initiates all transactions. The slave answers the questions that the maser device asks. The modbus protocol defines a specific format for these commands. It is up to your labview/scada program to implement this protocol and ask the questions in the proper format. The master device can read or write to plc inputs, outputs, input registers, or holding registers.

http://en.wikipedia.org/wiki/Modbus

http://modbus.org/docs/PI_MBUS_300.pdf