Siemens Industry Online Support
Siemens AG
Entry type: FAQ Entry ID: 109759818, Entry date: 01/25/2019

Why do problems occur when operating SIMATIC devices with touch screen displays?

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  • Associated product(s)
In industrial environments it might happen that electromagnetic fields interfere with the functionality of SIMATIC devices with touch screen displays. Although the SIMATIC products have been tested and certified in compliance with the relevant CE standards, it is possible that additional connected devices (USB, VGA, LAN, etc.) nevertheless cause EMC problems and affect the SIMATIC devices.

In the following we describe the faults that might occur and explain the measures to be taken to improve the electromagnetic compatibility of your device.

The following faults might occur through EMC problems.

Error scenarios

  • The device can no longer be operated via the touch screen
  • USB devices are no longer recognized
  • Touch screen inputs happen at incorrect points on the screen

You have the following options for reducing EMC problems.

How to reduce EMC problems

  • Disconnect the power supply from the device and from the connected USB devices of other devices that can create electromagnetic fields (isolating transformer, for example).
  • Decentralized execution of the equipotential bonding.
  • Improvement of the grounding system (low impedance) of devices with high load (converters/motors).
  • Physical separation of data cables and power cables.
  • Additional shielding of EMC-prone data cables.

Generally, in an industrial environment you should only use suitable and appropriately tested devices to minimize problems during operation.

Additional Keywords
Electromagnetic compatibility, IFP, ITC, Panel, Panel PC, HMI Panel, Comfort Panel, Basic Panel, Pro, Multitouch, BP, TP, EMC, Interference, USB, Equipotential bonding, Grounding, Touch, EMC disturbance

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