Troubleshooting Wire Feed Speed Issues on Miller S74
Matt Bush avatar
Written by Matt Bush
Updated over a week ago

The robot commands the wire feed speed and voltage/arc length settings to the Miller welding equipment using analog outputs from the robot. If you are not seeing the correct settings on the welding equipment there could potentially be an issue with the analog outputs of the robot. This guide will walk you through the various tests that can be performed to ensure that the system is working as expected and help narrow down where an issue may exist.

Testing the Analog Output

On the IO screen of the robot controller, you can test the analog output by using the slider in the lower left of the screen that is labeled wfs. The range of the output is a 0 to 5V signal out to the feeder, 0V = 50 ipm on the feeder, and ~4.9V = 780 ipm on the feeder.

Any voltage higher than this will result in the feeder going into a fault state where it is kicked out of the remote robot control. You will see on the feeder that the screen will change and the window on the left side of the feeder will display 9.9.

If you move the slider labeled wfs you should see the output on the feeder (right side display) change as it is moved. If you do not see changes on the feeder we will need to investigate further to understand where the issue is located.

Ensure Connections are Secure

There are several places to make sure that the connections are secure starting with the cable that runs between the robot controller and the welding equipment. Under the robot controller is two cables with screw-on connections, these connect to the Insight Core and the Feeder with the larger cable going to the Insight core (gray box located beside the welding equipment under the table)

and the smaller cable going to the feeder. We will be testing the larger cable for the analog settings.

Make sure that the cable is seated fully and is tight at the connection at the robot and the insight core, it is the cable connection on the left side of this picture

Make sure the connection is also fully seated and secure at the insight core

Also, ensure that the connection from the insight Core to the feeder is seated fully and secure at the RC21 connection.


If those cables are secure we will want to make sure that the wires in the robot controller are secure. Using the door key that is attached to the door, open the door to the robot controller. You will see a bank of IO connections that looks like this

We will pull the green block that is on the far right of the picture and has a label above it that says Analog.

Once it is pulled you will want to make sure that all wires are secure and installed properly. You can see the labels on the connector for each connection point, we are concerned with the wires in the ports marked AG, AO0 and AO1.

The AG connections may vary on your system from the picture above as all AG points are connected. Make sure to reconnect the green block to the IO module before proceeding to the next step.

Testing Output from Robot to Insight Core

Remove the cable at the back of the insight core

Using a multimeter set to a DC voltage scale of at least 10V probe pins H and F in the connector and measure the voltage.

The voltage on these pins should be the same as the voltage commanded on the IO screen of the teach pendant.

On the example below you can see the TP is set to a wfs setting of 3.09 VDC.

Using your multimeter probe the pins and verify the signal is correct. If the signal is not correct please contact Hirebotics for further support.

Reconnect the cable to the Insight core before proceeding.

Testing the Connection at the Feeder

The robot is connected to the feeder at two locations. The larger of the cables is where the wire feed speed command is sent to the feeder.

Remove that cable from the feeder. You will be measuring the voltage on pins 9 and 10 of that connector.

You should get the same reading on these two pins that you got on the Insight Core pins and it should match the output signal being sent from the robot.

If you are not getting the correct signal here, the Insight core box is most likely the issue and will need to be replaced.

If the signal is correct and the wire feeder is not displaying the correct voltage or the voltage is not moving as the analog output is changed on the robot teach pendant most likely the issue is with the Feeder. You can contact your authorized Miller repair center for further support. If you do not have an authorized Miller repair center you work with please contact Hirebotics for further assistance.

Did this answer your question?