Modbus

Question

question

Manikanta asked Jul 24, '23 Manikanta commented Aug 1, '23

Modbus

I am trying to get a data from a universal robot in URsim environment. I found the address of the robot to be connected. and connected according to the steps https://www.universal-robots.com/articles/ur/interface-communication/connecting-to-client-interfaces-within-ursim/#:~:text=Within%20the%20virtual%20machine%20open,of%20the%20robot%20within%20URSim.

I am trying to get the joints data of the robot while it is running into flexsim using Modbus connection

According to universal robot website https://www.universal-robots.com/articles/ur/interface-communication/modbus-server/

address (registers 270 to 275 gives a joint data of the robot)

In flexsim I emulated the connection as

detailed model Emulation example flexsim question.fsm here i am basically testing whenever a data comes from the register create a object on queue / change the colour of the queue using control registers. But when i run the model no change in the property of queue.

I doubted whether the connection is good and checked with qModMaster https://sourceforge.net/projects/qmodmaster/

It seems i am getting data from the URsim robot for the Base joint which is in 270 register. But it is not reflecting in the flexsim model.

How do i check whether flexsim is receiving data from the address by using MODBUS TCP connection. Is there anything I could do alternatively in the model like populating the data in global table. Help me in this regard so that I could get data from the robot.

Software Version:

FlexSim 23.1.3

modbus tcp

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Answer 1 · 2023-07-24T09:34:48Z

Felix Möhlmann answered Jul 24, '23 Manikanta commented Aug 1, '23

The software you are using to check the connection is emulating a modbus master/client, so I would assume that the robot is acting as the slave/server. As such FlexSim should also be set up to serve as a client instead of a server.

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Manikanta commented · Jul 24, 2023 at 06:19 PM

Hi Felix

I changed into client,

But the changes are not reflecting in the model, is there a way for me to check whether flexsim is getting the data from the robot using actions in control register or like writing the values in global table.

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Felix Möhlmann Manikanta commented · Jul 24, 2023 at 07:05 PM

Try checking the box to poll for changes. To show whether any values are received I'd suggest to print the values to the output console.

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Manikanta Felix Möhlmann commented · Jul 24, 2023 at 08:04 PM

Hi felix thank you

I could now confirm that flexsim is getting data from the robot through modbus connection. I have few doubts regarding how to convert these data first i need to get a signed integer as these are unsigned. I don't know whether clicking 16bit int gives the same functionality in the register type.

Next thing is i am trying to get the robot joint values in degrees

What kind of code should I use.

Also, i could see that output console is showing the data only there is a change in the value. What should i do if I just want to view the value when the value is not changing (i.e robot is not moving).

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