Procedure

From SS's help site:

Your SimpliSafe system has a built-in Test Mode to let you test all of your sensors.

From the keypad, go to the "Menu' and select "Test Mode'.  Follow the instructions below for each sensor that you'd like to test.  The Base Station will announce the sensor type to confirm that it has received the signal.  If you have a professional monitoring plan, you will receive a phone call confirming the test.

Sensor Testing  Instructions (while in Test Mode):

Motion Sensors:
Press the Test Button on the top of the Motion Sensor. For an accurate test, leave the room for the sensor you are testing then wait 15 seconds. Re-enter the room and the Base Station will say "Motion Sensor.'

Glassbreak Sensors:
Press Test Button on the top of the sensor then clap your hands loudly near your windows. Glassbreak sensors will respond to any loud sound in Test Mode (whereas normally they only respond to breaking glass).

Entry Sensors:
Open and close protected doors and windows.

Panic Buttons:
Hold the Panic Button down for 2 seconds.

Smoke and CO Detectors:
Hold the Test Button on the front of the sensor for 4 seconds. The sensor will beep 3-4 times.

Extra Siren, Water, and Freeze Sensors:
Press the Test Button on the top of each sensor.

Press the left arrow to exit Test Mode.

No worries! As long as you're in test mode, you should be good to go, but even if you hypothetically do something that causes a reaction by the system, they SHOULD call you first and you can cancel the dispatch at that time.  Happy SimpliSafe'ing!

I have multiple smoke detectors (6) and I test them all while in Test Mode.  C.O.P.S. will call me after each one is tested.  They told me that even though it's in Test mode they MUST verify there is no fire, therefore they make the call.  Seems kind of redundant, but at least I know for sure that they are getting the alarm signal at the control center.  Most of the time the phone is ringing before I get off the ladder.

If you are on the Total Command plan, 24.99, I put my system in test via the keypad, test the first smoke (there are six in my house and 3 Co's). It will sound off with the base and aux siren and COPS, as posted with Route 66 Guy, will call.  I then ask them to put the entire system on test for 1 hour.  I then test each of my smoke and Co sensors, and get 1. the sirens and 2. a push alert that the signal was received.  I also do my system maintenance at the same time, using compressed air to clean the smoke and Co censors, check all sensor mountings to make sure they are secure etc etc. All gives me peace of mind, which I do once every two months.

Thanks all for the additional comments.  There's always more to learn.