The PIR sensor on the Multisensors that we have are very sensitive to sunlight which can cause false motion tracking from shadows or extreme direct sunlight.
It is highly recommended to disable the motion sensor when used outside (parameter 4 [1 byte] = 0), but if you plan to use the motion sensor outdoors, I would suggest that you set the sensitivity of the motion sensor lower and angle the motion sensor away from sunlight if at all possible.
The Multisensor 6 has 6 sensor settings using Parameter 4 [1 byte]:
0 = Disable
1 = Very Low Sensitivity
2 = Low Sensitivity
3 = Medium Sensitivity
4 = High Sensitivity
5 = Max Sensitivity
By default, this setting is set to the maximum sensitivity (Parameter 4 [1 byte] = 5)
It is advised that if you are seeing false motion tracking, run trial and error to determine the best sensitivity from a range of 0 - 5 by going down 1 sensitivity level after every test (first 5, 4, 3, 2, then 1).
Setting Parameter 3 [2 byte] to 10 to allow a PIR sensor timeout of 10 seconds after detecting motion, which can be used to rapidly determine the best settings for motion use outdoors.