Jump to content

Modbus Comunication


Recommended Posts

Hello, i'm from Uruguay (sorry for my english). I'm ussing the f7 inverter (yaskawa) in comunication with a touch screen and the ac motor.

My motor moves a wagon in a rail, forward and revers, when the wagon arrives to the end of the rail it touch a sensor (that happen in both sides).

I need to know how can i do to stop the motor in this case and only be able to go to the other side with the wagon using the touch screen.

I think it could be using "macros" working in the EasyBuilder program.

Thank a lot to anybody who could help me.


Link to comment
Share on other sites

Hello fede00


Welcome to the forum.


Firstly, can you give some information on the touch screen. Is it currently talking to the drive, does it have any intelligence on board i.e. onboard PLC. Is it connected to other things? is this a working system or a brand new installation?


Best regards,

Link to comment
Share on other sites

I have conected the inverter yaskawa f7 to the touch screen "maple system", "silver series",

by modbus comunication, and the motor. I solve some things of remote control of the inverter

by the screen comand using macros in the program which use to create and compile the screen programs (easy builder). The code is:

bool FWD=1

bool STOP=0

bool FINFWD=0

bool CLOSE=0

Macro_Command main()

GetData(FINFWD ,4x_Bit_Binplc ,4406,1)

If FINFWD==1 Then

SetData(STOP ,4x_Bit_Binplc ,200,1)

SetData(CLOSE ,LB_Binplc ,20,1)


SetData(FWD ,4x_Bit_Binplc ,200,1)


End If


End Macro_Command


And the same for going reverse...


the idea of using the touch screen is because is easier for the operator personal to contol the variable speed(inverter), with graphics and those things...


I have more questions about, do you know something to tell me?

thank you very much!


Link to comment
Share on other sites

Hello fede00


The HMI panel is designed to be used with a plc and if you were using a plc, there would be no problem doing what you want to do.

Some drives have some plc type functionality and this may be the case with the Yaskawa, I do not know.

It may be possible to connect the limit switches to spare inputs on the Yaskawa drive and read these via MODBUS and then use the macro language to achieve your requirements, or to use some internal logic on the Yaskawa to set the direction based on the last limit switch etc.

Unfortunately, I do not know the Yaskawa well enough to give you good advise in this regard.


Another option is to add a small modbus enabled plc, or use an OCS such as the Horner range of products.

The OCS is an Operator Control Station and is an HMI panel with a built in PLC.


Best regards,

Link to comment
Share on other sites

how can i do to improve the communication between a touch screen (as master) and more than one plc like the yaskawa f7 inverter (as slaves) ?

the problem is the speed of comunication, more than 19200 baud it doesn't work and in 9600 is slow reading

parameters sent from the screen.


Link to comment
Share on other sites

The way to do that would be to use a small PLC to handle the communication to the VFDs using something faster such as Profibus, then use the HMI to just access subroutines in the PLC to execute your conditional programming.




Marke, that Maple Systems HMI has an option to be a Modbus Master, so technically it can be used like this.

"He's not dead, he's just pinin' for the fjords!"
Link to comment
Share on other sites

But can the Maple systems read I/O and set relay latches to set the directions?

I have no experience with this device so suspect that some external I/O would be required to connect to the limit switches.


Best regards,

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...