sendCommand vs postUpdate

Setup, Configuration and Use Scripts & Rules
3

I’ve been trying to understand this better myself. I’ve read a bunch of documentation, and I’m still a little confused.

I have the following rules for a servo which I plan to control my blinds:

// Servo
rule Servo
when
	Item Servo received command
then	
	if(receivedCommand==UP){
		sendCommand(Arduino, "105;10;1;1;29\n")
		}
	if(receivedCommand==DOWN){
		sendCommand(Arduino, "105;10;1;1;30\n")
		}
	if(receivedCommand==STOP){
		sendCommand(Arduino, "105;10;1;1;31\n")
		}

I also have a rule to open the blinds at 0700:

rule "OpenBlinds0700"
when
	Time cron "0 0 7 * * ?" // every day at 0700 (format 'second minute hour day-of-month day-of-week year(optional)')
then
	sendCommand(Arduino, "105;10;1;1;29\n")
	println("Blinds Opened at 0700")
end

In my OpenBlinds0700 rule, could I just use a postUpdate(Servo, UP) and have that change trigger my ‘Servo’ rule? I think this would require changing the ‘Servo’ rule from:

 when
    	Item Servo received command

to:

 when
    	Item Servo received update

Am I understanding this correctly, or is there a better way to do what I’m trying to do?