Extension of Inputs Outputs interfaces with MODBUS nodes.
If the number of I/O interface ports on the controller board and tool head is not enough then it is possible to extend by installing external MODBUS nodes.
They are connected to the UR controller via the Ethernet and the UR controller programming method is prepared to read and set these external I/O signals as they were a part of the integrated controller.
Example of Modbus configuration using BK 9050, KL 1408, KL 2408 and KL 9010 Modbus modules.
BK 9050 = Modbus Controller with Ethernet port for IP configuration.
KL 1408 = Modbus 8 port input module.
KL 2408 = Modbus 8 port output module.
KL 9010 = Modbus End terminator.
The IP address of the Modbus node has to be defined in the Robot configuration.
Tick the “Show advanced options” and press the “+” sign.
In our case the Modbus node has been setup for the IP address of 192.168.0.10 and therefore we have to define this for the Robot.
Press the Keyboard icon next to the IP: address field.
Key in the IP address of the Modbus node and press “OK”.
Press the “+” sign just below the “-“ sign and in same row as the IP address we are defining.
Define the first entry as an Input. Press the Keyboard sign in the middle.
Define the first Modbus signal address as “0” which is the local address on the Modbus node for input 0 (first input on Modbus node).
This will activate the Modbus node and a Green light will appear. In this case the Input is high – indicated by the dark grey box next to the green light.
Each Individual Input and output has to be defined in this manner.
Press on the “+” sign below the previous Modbus definition to define the next Input.
Define this next Input like the previous one, but this one has the next local address which is “1”.
In this case the Modbus node has 8 inputs and therefore address 0 to 7 has been defined.
After all the Inputs has been defined – then define the Outputs in similar way.
Continue until all 8 Outputs have been defined (local address 0 – 7).
In case of more than 8 in and 8 outputs the Modbus “scan” frequency maybe has to be reduced.
If there is yellow light in some Modbus nodes representation in the UR robot menu (not on the node) then the frequency has to be reduced until all in/output is green – properly 5 Hz is recommended.
Make sure there is no more flickering yellow light and all is green which indicates that the Scan frequency is correct.
Press the I/O tab and notice that there is now a Tab called the Modbus.
This screen shows the status of the Modbus Inputs and Outputs and the Outputs can be manipulated. On the right side all outputs has been set high.
The Modbus Inputs and Outputs are no available to be used in the program structure.
Modbus Inputs ready to be used. Modbus Outputs ready to be used.
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By Zacobria Lars Skovsgaard
Accredited Universal Robots support Centre and Forum.