FX1S and Modbus?

Neil E.

Member
Join Date
Jul 2008
Location
Toronto
Posts
6
I've been using Mitsubishi PLCs for about 15 years in control panels for stand alone packaging machinery. The little FX1S does all I need with it's variety of BD boards. My only complaint is the lack of a port for program monitoring when an HMI and BD board are both connected to the PLC.

I'm looking at the 485BD board to communicate to one or more VFDs. Specifically the KBVF with it's add-on communication board. The KBVF uses a Modbus protocol that doesn't look to be compatible with the 485BD.

The Modbus data packet doesn't use an ENQ/ACK/NACK. Any recommendations on how to communicate with the drive using the 485BD board?
 
Hi Neil,

Have you ran this one by Mitsu Tech Support? I seem to recall they had a sample program that implemented Modbus through "brute force" ladder programming
 
I used to be on a first name basis with all the tech support people in Chicago back in the Medoc days, but they've all retired or moved on.

When I recently asked tech support, they flat out said they don't know how to get the FX1N-485BD to work with Modbus. Their next statement was the typical "but we have a Modbus module for the new FX3N". They are not very helpful anymore.

I was hoping someone here might have done this before.
 
Last edited:
I have PLC FX1S and module FX1N-485-BD. I want to connect this PLC to inverter D720S.
I try configure modbus rtu, but I can not. Please help me for:
1. Using RS intruction??? cannot From - to. And I can't understand this intructions (RS): register, address,
2. Wring: choose one pair orr two pair.
Please help me, many tks
B.R
Kip
 
With the FX1S you do not need modbus it can use the N:N network this means setting the inverter to mitsubishi protocol & the 485 Board to the same.
I do not have the detals but there are manuals on the Mitsubishi website
Edit: Just realised that the N:N network for inverters will not work on FX1 only applies to FX2 & 3 etc.

Try this manual it may help
https://www.lcautomation.com/wb_documents/mitsubishi/mitsubishi fx3 series plc user manual.pdf

Just found this
http://www.inverter-plc.com/plc/melsec/FX3U SERIES PLC,MODBUS Serial Communication Edition.pdf
 
Last edited:
Apparently the FX1 does not support Modbus nor does the BD board.
You will need at least FX3U (C) and the 485IF board not the BD.
However you could probably roll your own using the BD board.
You would have to set it up as no protocol, populate the send registers with the correct data etc. etc. however this would probably take more programming than you have memory. To be honest you would be better off going with FX3U & 485IF & use modbus protocol setting so all the work is done for you.
 

Similar Topics

Hi I have a Melsec FX1S-20MR, which has been programmed. I would like to copy the program to a new FX1S-20MR? What are the possible ways to do...
Replies
4
Views
568
Hi Guys, Can anyone help with an easy problem? I have retrieved a prog from a faulty Mitsi FX1S plc. I managed to open the file by using a...
Replies
5
Views
2,004
Good evening, Let me introduce myself, I am a 70 year old retiree, my name is Guy During my professional life I programmed plcs of various brands...
Replies
5
Views
2,648
Minutes ago, I got some pics sent to me from a fellow Tech's customer. They asked me if I've ever worked with a Mitsubishi PLC. I said no, but I...
Replies
19
Views
6,554
I haven't needed to work with a Mitsubishi PLC until now. But I just got a call from another tech working on a customer's machine, wondering if I...
Replies
5
Views
2,129
Back
Top Bottom