MELSEC FX2N PLC Communication

Hi,

Kindly bear with me i am totally new to PLC.
We are using MELSEC FX2N PLC for our project.We are developing a software which will communicate with the PLC and will get all the outputs from the PLC which is set in PLC.

I got the manual, as i am new , i didn;t understood anything from the manual. I just need to get the outputs from the PLC.

Please tell me what are the basic things i should know before communicating with the PLC ?

how to set the configuration for the communication ? i think its 9600,N,8,1 which was set by vendor from who we got the PLC. But i was curious to know how to set that.

What commands should i send to get all the outputs from PLC?

Your help will be highly appreciated

Dhiru

What do you mean by output, the digital output or values from the memory area in the PLC ?

To program the PLC you will need GX Developer or GX-IEC Developer programming software and a communication cable which is called an SC-09.

To get data out of the front port of the PLC to a PC you will need additional software depending on what you want and what format you want it in.

Simple answer is you need software capable of reading addresses from the PLC, such as an OPC Server or Mitsubishi's MX Component. What are you trying to use for the communication? A program you write in VB or VC or what?

What you intend to do with the the data and in what programming language determines your requirements.

I want to read digital output from the PLC.
which additional software is needed to get the digital output ? please let me know

we are writing the program in vb.net using Serial component

dhirub4u said:

I want to read digital output from the PLC.
which additional software is needed to get the digital output ? please let me know

we are writing the program in vb.net using Serial component

Click to expand...

You alredy have the answer in Crossbows post:

Simple answer is you need software capable of reading addresses from the PLC, such as an OPC Server or Mitsubishi's MX Component.

If you are writing in VB, I would recommend MX Component. It's a set of ActiveX controls to handle the communication to the PLC and get the data for you.

Is it mandatory that i have to use MX component for writing code in VB. Is there any otherway other than MX component ?

The communication protocol for the front port is proprietary, Mitsubishi doesn't share it. So unless you use a driver someone has already written, you're going to need to figure out the format for the messages yourself.

Like I said, buy MX Component or some OPC server.

hello dhirub4u!
sorry! my english is badly!then maybe you can't get my mean!but I think said more and more ,you can understand!ahh ahh
There are many kinds way in FX2N 'PLC communication.For expmle:computer link ; programming port;etc
If you use computer link,then you might buy a moudle,the name maybe is RS485BD;I forget.but I used the programming prot even.use sc-09 cable is OK;although these is not understanded to us.is you need ,i can sent to you.
I make software with Visal Basic. write and read to the plc'data.this is way only.if you have more money ,you can buy OPC server and communication dll form Mitsubishi
if you can't catch my way ,you can wirte problem in this.or sent mail to me,or call me.

Hi Dhirubhai,

Consider using KEPserver to communicate your FX with VB application.

dhirub4u said:

Is it mandatory that i have to use MX component for writing code in VB. Is there any otherway other than MX component ?

Click to expand...

You can buy a driver or a progarm from me send me email

Doug Hylton

Buy a 232BD board, install it, write program in GX Developer to transfer say D100-D200 out of the comms port (it comes with examples)store any bits/words you like in the 100 addresses (transfer i/o or integers to the words & VB will read it using the standard comms.

A driver is needed

parky said:

Buy a 232BD board, install it, write program in GX Developer to transfer say D100-D200 out of the comms port (it comes with examples)store any bits/words you like in the 100 addresses (transfer i/o or integers to the words & VB will read it using the standard comms.

Click to expand...

Its not quite as simple as you state. First I think you are talking about MX-Components not GX-Developer. GX-Developer is the ladder programming editor. MX-Components is the software driver that connects the PLC to the programming environment (visual basic or what ever) that is sold by Mitsubishi for about $ per computer.

Another approach is to purchase an OPC server for about $ per computer.



The protocol between the Mitsubishi PLC and the computer is not published and it is complex so unless you have a few weeks time a driver is needed . There is no easy way to communicate with the PLC without a driver.



I have written drivers for both the FX2n PLC and the FX3u PLC. My drivers support background polling. When the driver detects that a PLC register's value or bit state has changed, it generates a Change event, passing the address of the point and its new value. The developer provides a Change event procedure, where the handling of these events can be specified.



The drivers also support writing to or reading individual points.

1. Monitor Bits X,Y,M and S and Monitor D Registers
2. Set or Reset Bits X,Y,M and S and Write to D Registers

See my home page for more information

No I'm correct if you read the post correctly.

You install the 232BD board, write the comms function in the plc using GX (the board comes with sample programs )then write a simple VB app using commctrl , the plc program will send the data,all the VB program has to do is capture the data & read it into the comms buffer.
The 232BD board sits in a little area on the plc, it can be used in non protocol mode to send & receive info in buffers
I have done this a few times in VB.
The board is about £90 & is cheaper than mx component.
MX Comp is useful if you need to use FX protocol.

parky said:

No I'm correct if you read the post correctly.

You install the 232BD board, write the comms function in the plc using GX (the board comes with sample programs )then write a simple VB app using commctrl , the plc program will send the data,all the VB program has to do is capture the data & read it into the comms buffer.
The 232BD board sits in a little area on the plc, it can be used in non protocol mode to send & receive info in buffers
I have done this a few times in VB.
The board is about £90 & is cheaper than mx component.
MX Comp is useful if you need to use FX protocol.

Click to expand...

Excuse me you I see you are talking about using RS(FNC 80) and writing code in the ladder. I have used the RS function a number of times and it works find for a limited data exchange at a short distance and it’s low cost way of doing it. It just depends on what your requirements are.