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Guidelines to avoid interference

To work reliably, readers needs an environment without interference. Here's how you can ensure these conditions.

Avoid interference between readers

If you mount readers too close together, they may disturb each other's ability to read cards. To avoid this interference, please keep the following distances:

  • Simultaneously operating readers
    These are readers that work independently of each other, e.g. in Autoread mode.
    Keep a minimum distance of 200 mm between any 2 readers.

  • Sequentially operating readers
    These are readers controlled by a host so that only one reader is active at a time.
    Keep a minimum distance of 50 mm between any 2 readers.

    If a certain reduction in read range is acceptable, you can reduce the distance even further.

Avoid interference from other sources

Readers are susceptible to interference in the frequency range from 1 kHz to 1 MHz. To avoid interfering signals, keep a proper distance between the antenna field and

  • the switch mode power supply circuitry
  • the wiring inside the device where the reader is integrated.

Power filtering in BALTECH readers prevent interference through power supply lines, which are the most likely source of interference.

Avoid rain interference on ACCESS200 outdoor keypad readers

Our readers are designed so that water drops will drip off before becoming large enough for interference. However, if the surface of an outdoor-mounted keypad reader becomes dusty or the reader is mounted at an acute angle to the floor, drops may become larger and cause interference: Similar to your smartphone screen, large water drops on the reader surface may be sensed as a tap with a finger or prevent a tap in another area from being detected correctly.


  • Mount the reader upright/perpendicular to the floor.
  • Mount the reader at a protected spot or add protection against direct exposure to rain.
  • If this isn't possible, wipe the reader on a regular basis or let users know to wipe over the surface in case of malfunction.