INTRODUCTION

When a machine isn’t working as expected, the HMI is often the first place a technician looks—and the I/O screen is one of the most useful tools. It shows the live status of inputs and outputs, helping you figure out what is (and isn’t) happening inside the system. Now that you’ve learned how the HMI controls and monitors your trainer, this activity will introduce you to the I/O screen to troubleshoot issues and verify system performance.

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LAB MATERIALS

Basic Automation Trainer
Automation Direct HMI
RS232 serial communication cable

Ask an instructor where to find the above items if necessary.

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LAB INSTRUCTIONS

In this lab you will be introduced to the I/O Screen on the HMI.

INDUSTRY CONNECTION

I/O screens or indicators are used to troubleshoot and monitor a machine and its process.

Inputs and Outputs

"I" stands for inputs and "O" stands for outputs. This screen will report the status (either ON or OFF) of every input and output.

Inputs (I)

Inputs are signals or data received by the machine from external devices such as sensors, push buttons, switches, and emergency stops.

These represent conditions or commands that the machine must respond to.

Outputs (O)

Outputs are signals sent from the machine to external devices like relays, motors, lights, or actuators.

These represent actions or responses triggered by the machine based on input status or programmed logic.

I/O Screen

NOTE

Press the screen change push button labeled "I/O Screen", as shown in the photo below.

This will take you to the "I/O" screen.

Main screen of the HMI with an arrow pointing to the IO Screen Button

The "I/O" screen should look somewhat like the photo below.

IO screen with inputs and outputs listed in respective columns. Next to each input or output is a circle. See further explanation in the text.

Input and Output Indicators

The circle to the left of each input or output indicates whether the inputs or output is ON or OFF. If the circle is green, the input or output is ON. If it is gray, the input or output is OFF.

Input ON

An Input is ON when 24 volts is present at the input. (So when a button is pressed or a sensor is triggered.)

Output ON

An Output is ON when it is supplying 24 to turn on a device. (So when a light is on or the pneumatic valve is actuated.)

Observe the I/O Screen

TASK

Press then release the E-Stop while watching input X001 on the I/O page. The circle to the left of it should start off green (when the E-Stop is released), then turn gray when the E-Stop is pressed.

TASK

Press then release the red push button while watching X002 on the I/O page. You will see this circle turn from gray to green.

INDUSTRY CONNECTION

An I/O screen on an HMI can be a useful tool for troubleshooting. If an indicator does not light up when you expect it to light up (or vice versa), then a technician knows where to investigate further.

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SUMMARY

You should now be fairly familiar with the functions of the I/O Screen.

Indicators show whether an input or output are activated.
Inputs and outputs can be used to troubleshoot a machine.

If you have any questions, ask an instructor.