Why "received command" run twice in .rule?

Setup, Configuration and Use Scripts & Rules
, ,
1

.items:

Dimmer DimmedZal6 "DimmedZal6 [%d %%]" <slider>

.sitemap:

Slider item=DimmedZal6

.rules:

rule "RULE_Dimmer_DimmedZal62"

when

	Item DimmedZal6 received command

then

	logInfo("Exec4", 'DimmedZal6 received command: ' + DimmedZal6.state.toString)

end

/openhab.log:
2017-02-27 19:29:53.043 [INFO ] [eclipse.smarthome.model.script.Exec4] - DimmedZal6 received command: 0
2017-02-27 19:29:53.235 [INFO ] [eclipse.smarthome.model.script.Exec4] - DimmedZal6 received command: 0

I change slider value from page http://192.168.1.3:8080/basicui/app?sitemap=demo

image.png824×521 38.9 KB

And I getting twice “received command” from .rule.

Why?

2

Seems reasonable for sliders to send multiple commands when being slid.