How often does Blynk send commands

If I have something in my loop like:

if (t < s.lowTemp_setpoint) { //temp is below set point
digitalWrite(heat1, HIGH); //turn on the first heater
led_heat.on();
}

else …
led_heat.off();

and this runs without any delay. Is it going to constantly use data to send the LED off (or on) command to my BLYNK app? Or will it just send it if it changes state. If it sends it every time thru the loop, that could really tie up the network, and use data non stop, ???

As most any IoT application, Blynk is generally in a constant link with the server… but as for the frequency of sending data, that is entirely up to how you set Widgets in BLYNK_READ() frequency mode or mash buttons/sliders, etc. in BLYNK_WRITE() functions, and how frequently you send Blynk.virtualWrite() commands from the device.

In other words… however fast (within limits of the overall network) and however much or how little you want it to be…

That all said, do NOT put Blynk commands in the void loop() where they WILL try to run thousands of times a second… you must use timed functions instead.

Blynk is very compact and efficient. And whenever there is potential for heavy background bandwidth usage, you are warned in the documentation or when setting such in the Widgets (E.G. Push Notifications set to high priority).

The technical protocol for actual communication is as follows (as per a forum search for keywords like protocol, etc)…