This is a checklist used to restore connectivity between the Siemens PLC and the ET 200SP.
This article is part of the DigiKey Field Guide for Industrial Automation
Location: Program It → Distributed I/O
Difficulty: 
Engineer — difficulty levels explained
Author: Aaron Dahlen | MSEE | Senior Applications Engineer, DigiKey
Last update: 06 Mar 2026
Device Configuration
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Verify the TIA Portal configuration matches the real-world devices. Pay attention to version:
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Version of the ET 200SP Interface module.
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Version of the Server Module. Don’t make my mistake and assign V1.2 when the actual version is V1.12. In this case, the base V1.1 is required by TIA Portal.
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Version of each of the submodule(s).
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Power
- Power to the ET 200 SP and submodules with attention to potential groups.
Network Connectivity
- Use the ping command to verify basic network functionality for both the PLC and ET 200 SP.
TIA Portal Configuration
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Apply the PROFINET device name e.g., io device_1. I’ve included Figure 1 as a reminder as I often forget this step and then wonder why the system diagnostics displays the hardware component not available message.
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Verify that the TIA Portal configuration matches the real-world port use (e.g., X1 vs X2).
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Set the partner port (“ANY port” vs PLC specific).
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Compile and the download the hardware and software.
Figure 1: PROFINET name screen.
Troubleshoot using the PLC’s Diagnostic Data
Figure 2 presents the PLC diagnostics screen for. As part of the troubleshooting process, it is sometimes useful to power cycle the PLC. In this example we see:
- 12:18:11: Supply voltage missing
- 12:18:20: Reboot
- 12:18:28: Hard fault from an AS-i networked device
Figure 2: Diagnostics screen for the PLC.
About This Author
Aaron Dahlen, LCDR USCG (Ret.), is a Senior Applications Engineer at DigiKey in Thief River Falls. His background in electronics and industrial automation was shaped by a 27-year military career as both technician and engineer, followed by over a decade of teaching.
Dahlen holds an MSEE from Minnesota State University, Mankato. He has taught in an ABET-accredited electrical engineering program, served as coordinator of an electronic engineering technology program, and instructed military technicians in component-level repair.
Today, he has returned to his home in northern Minnesota, completing a decades-long journey that began with a search for capacitors. Read his story here.