If the communication fails, check that

  • the infrared devices are positioned correctly. The infrared windows should be within 30 degree angle, no further than one meter (39 inches) and no closer than 1 cm (0.4 inches) from each other.

  • nothing is blocking the path between the infrared windows of the devices.

  • there is no other infrared device nearby.

  • your Polar wrist unit is in the connection mode.

  • the battery of your Polar wrist unit does not need replacing (i.e. low battery symbol on the display).