Hmi ??????

cindy guest

Guest
C
Hi guys we have been here before,

Well I have looked into buying an HMI instead of trying to build a mimic panel and I have come up against a snag. So far all the HMI's that I have found that interface with the FXon series will only work on one plc, so iether the master or the slave but not both.

I sent an email to one of the manufactures about this enquiry and they resoponded that I would have to buy 2 one for the master and one for the slave.

This seems a bit excessive to me does anyone know of a way to do this without using 2? I dont even know hao that would work as the master and slave are talking to each other all the time too.


Help!!!.....??????
 
It makes sense that the HMI cannot work for two "apparent" masters. Conflict, don' cha know?

A conceptual description...
Connect the HMI to the Master. Any information from the Slave should be given to the Master then the Master gives it to the HMI. That way the HMI is only "aware" of one PLC, while actually servicing both the Master and the Slave.

You need to design something in the Master to handle the information between the Master and Slave.

The HMI reads data from a particular memory range in the Master. The HMI sees this as info from the Master... it is not aware of the Slave.

When receiving info from the HMI, the Master should know that certain locations in the receive area are for the Slave. Having received info from the HMI, the Master passes HMI info to the Slave.

So you need two data paths... Slave <--> Master and Master <--> HMI.
 
woops

Hi Terry,

I didnt think about that.:( I pressume when you said I "need to let the master know what info to pass to the slave" that would involve programming?

I dont know much about this :( can you tell?
 
Your HMI panel needs to communicate with the PLC. For point-to-point communications between a PLC and an HMI, the HMI is generally the master. That means that the HMI panel initiates all communications transactions. WHen the HMI needs to update its screen, it requests the necessary data from the PLC. When the operator hits the <Enter> key to send data to the PLC, the HMI panel generates the 'write data' command to the PLC.

Don't confuse that mastership (mastery, masterism?) of communications with the relationship between the two PLCs. It should be perfectly acceptable for the master PLC to be a communications slave to the HMI. On PLCs with multiple serial ports, it's possible for one port to be a master and another to be a slave.

What you need for your situation is an available serial port on each PLC. Each serial port should be configured as a communications slave. Then you need one of two options on the HMI.

The first option is for the HMI panel to have two ports available for communications with two PLCs. The other option is to use a communications protocol that supports multiple PLCs on a single communications cable. Sometimes the second option requires a network card in the HMI, sometimes it requires ports on the PLC and HMI that conform to the RS485 electrical standard.

It's a good idea to make sure that your mimic panel doesn't interfere with the ability to connect the programming software to the PLCs. It may be possible to use the PLC's programming port for communications with the HMI, but I wouldn't advise doing so. It makes debugging the HMI panel difficult, and it forces your technicians to disconnect the mimic panel when they need to monitor the PLC program.
 
Can you e-mail me at
[email protected]

I don't know what your budget is but I think you were on track with what you wanted to do before.

You can use multiple HMI's on any Allen Bradley network, but I'm not sure if you even need to.

Could you plese make a drawing or schematic of what you want todo including some sizes of what is needed to give a sense of scale.

Jim

Is the !@##$!@$Fx a Mitsubishi?
Does it have communication or Remote I/O modules that fit in the rack?
 
You beat me to it Jim. I was going to suggest AB as well. I've had 9 HMI's talking to 3 plc's before and it's not too hard to set up depending on what network you are using to communicate with.
 
Take a closer look?

I suspect throwing out the Mitsubishi's to go to A-B is not a realistic consideration economically, Cindy.

I haven't done it myself, or worked with your specific model, but the port on the FXo series is an RS-422/485 port. This can be electrically compatible with a multi-drop communications system. The Mitsubishi literature I have is old, but it shows multiple FXo PLCs on what they call an FX-485 network, which implies that the PLCs are addressable.

Now, then, what you need to do is:

1) Talk to your Mitubishi representative and find out if I am correct in thinking that there is a single master/multiple slave network for the FXoN PLC.

2) Find out if they have a HMI that includes PLC addressing as well as register adressing in the data format. As Steve pointed out, the HMI will be the master. If it can address two slaves, your problem is fairly simple.

3) Talk to another couple of HMI sources to see if they have the ability to adress multiple PLCs. One that I have used to do this with other brands is EXOR (www.exor-rd.com) but I'm sure others can do this as well.

4) Then pick the comm adapters, HMI type, and go with a vendor that you feel will do the job and give you some support on this project.
 
ok

Well guys I am now lost the information that has been provided is great but I dont know where to even start. I am going to take up toms advice and get intouch with a distributor.

I dont know much about the plc's we have at all, I have a copy of the program and a printed copy of the ladders. I finished college in July last year and I havent had any dealings with plc's since. we only dealt with plc's for a year and that was only 1 hour a week. Needless to say that makes me more than a novice! :( I have landed a job where they think that because I did it as one of my modules that I should know it all!! (wishfull thinking).

There is obviously no easy way to do this and maybe they will even let me go back to my old college to work it out with my tutor, but I doubt it.

I am hoping that my company will send me on some form of proper training to carry out anymore work as I am very quickly sinking.


Thanks for all your help and guidance.

Cindy
 
Don't let it get to you, Cindy. Your engineering education prepared you for going into the unknown, whether you realized it or not! Remember, engineering is not a body of knowledge - it is a discipline, a problem solving system that lets you go where no man or woman has been before! You shouldn't expect to know the answers at the beginning of the project, just know how to get them.

1) Define your objective: Display critical operating data and status

2) Select one or more approach a) old fashioned LED graphic display board b) one HMI for both PLCs c) one HMI for each PLC

3) Investigate the operating characteristics and critical positives and negatives of each approach - that's where the distributor comes in

4) Select an approach, outline the steps, and dive in. Do not try to think through the whole system before you start, just line up the resources you will need to solve each problem in turn as it crops up. Bear in mind that design is an iterative process - you will solve one problem, and the solution will create problems related to previously completed tasks. You go back, fix as required, and then proceed on again.

5) Do not be afraid to ask questions. Contrary to conventional wisdom, there are stupid questions. Contrary to your gut feeling, if you ask a stupid question it doesn't matter. Your mother will still love you, your payscheck will still be cashed, and you can take the knowledge forward. The only one who will be upset is yourself. Get used to it - don't let fear of looking foolish prevent your progress!

6) Be flexible - adapt as you go, but keep the initial objective in mind.

7) Don't search for perfection. It doesn't exist this side of the grave. An engineer is a person that can produce a system or device to provide a required funciton at an acceptable level of quality at a price the customer is willing to pay. (Note: that desn't mean allow sloppy work, it just means you can't keep tweaking forever to achieve a diminishing level of improvement.)

8) Don't lock in on an unimportant detail - keep that initial objective in mind.
 

Similar Topics

Hey everyone and anyone that can lend a helping hand. I have a project that I am being asked to add some animations of Solidworks or "3D" models...
Replies
5
Views
55
I copied a panel in factory talk HMI for an identical system. The label names are still the same as the original panel but I am trying to change...
Replies
0
Views
54
hi all i am new here i have a mitsubishi smart touch hmi i.e ms-60t-pe but i cannot find a software to edit and download a program in it any help...
Replies
3
Views
91
I HAVE SMART TOUCH MS-60T-Pe MITSUBISHI HMI BUT I CANT FIND A SOFTWARE TO EDITE AND DOWNLOAD A PROGRAM IN IT.......CAN ANYONE HELP PLEASE!
Replies
0
Views
45
Hi all, I am having an issue where some of my HMI push Buttons and Indicators go in to error when I navigate to a new screen. I am using a...
Replies
16
Views
317
Back
Top Bottom