Modbus Commands in UR e series

Prasanna

Hi @matthewd92
is there any command to use start, stop and pause the programs in UR through modbus.

in ur, only config inputs i can configure start, pause and stop but configurable inputs cannot be write in modbus.

I can use dashboard server, but still i want to know whether i can use modbus or not.

matthewd92

What version of polyscope?

Prasanna

E series 5.3

matthewd92

Go to the installation tab, click on IO setup and choose Modbus from the view menu. Select the input you want to use (needs to be a digital input) and select the action you want that input to have.  See attached picture.

Prasanna

I tried already.
But how can i write values to input from gui. For digital output such options are not available. 

matthewd92

Not sure I follow, there is no way to write to an input from the GUI.

Prasanna

Then how to teigger the input....
I use writesingleregister(138,1) to trigger output. How to write for inputs.
I tried by using modbus signals as you suggested but couldn't trigger the input

matthewd92

That is not what modbus is for, modbus is a I/O field protocol for adding additional IO to the robot cell that communicates back to the robot via the Modbus protocol.  For instance we use Turck TBEN junction blocks in the field when we have more than 16 inputs or 16 outputs in the cell.  These junction blocks allow us to attach additional inputs or outputs to the robot (switches, sensors, valves, etc) and then use Modbus to communicate the status of the IO to the robot and vice versa.  So to use the modbus input you would need to wire a switch or push button to a modbus expansion IO point and then connect that to the robot over TCP (ethernet).  Then when you push the button the robot would get notified of that over modbus and take action based on the defined action of the input (if any)

Does that make sense?  The robot is not intended to trigger inputs, only outputs.  Inputs are intended to be signals sent from other devices to the robot, so the robot is listening for the event to occur.  Outputs are the robots way of communicating out to other equipment and so that equipment is listening for the event to occur.

Prasanna

Hi @matthewd92
I totally agree with your point.
 But modbus is not only for attach additional input and output but also we can do access input and outputs by pc program using any programming languages such as python or java or any over ethernet without hardwiring of input and output as well.
Am using C# and i wanted to start and stop program using modbus. Is that possible???

matthewd92

Yes, using your C# program, write to the coil that you want to control, make a modbus server that the robot can connect to and then adjust the value of the coil when you want.

If you are doing C# though, why not do RTDE?  It's a much more robust protocol that UR provides as an interface to the robot, not only can you write registers from there you can also read the full state of the robot giving you the possibility to control more and know more about the robot.

matthewd92

Oh, and with a E-Series you also have to be in remote control mode for the play to work from anything other than the screen.  When in remote control though you can't have an external free-drive input.

Prasanna

Yes i know.... I tried that too

matthewd92

Not sure what is going on then, we send these commands to the robots via Profinet to boolean registers from HMI's, modbus/digital inputs using buttons and don't have any issues.  I would look at the C# server that you have written and start with making sure that it is serving the correct values to the robot modbus client.

Prasanna

Is that possible to start stop the program from hmi using boolean registers through modbus

matthewd92

You can’t access the Boolean registers through modbus, you’d have to use Profinet or Ethernet/IP

Prasanna

Okay.... I used dashboard server itself.... So that i can get the status as well