Blinking of Hue lights via Hue Bridge on alarm

Spent half my Sunday figuring out (incl looking for help in these forums) if I could use variables, delays, repeats, If-Then to make my Hue lights (connected via Hue Bridges) blink (not flash). All to prepare for triggering a rule based on HSM alarming. But didn't succeed...

Does anyone have good advice on how to control blinking of Hue lights via Hue Bridges based on HSM alarm?

Thanks in advance

First, what do you mean with the difference between "blink" and "flash"? (The terms are nearly synonymous to me, so I'm just trying to understand the desired outcome--not trying to be picky about the word we use, so hope it doesn't appear that way!)

Second, if you are using Hubitat's stock Hue Bridge integration, it does not have a way to do this. Lots of bulb/dimmer/switch drivers in Hubitat don't, so this isn't unusual; it's not a "standard" command required by any Hubitat capability. That being said, some drivers do implement the "Flash" command, so it's become sort of a pseudo-standard and is available as a command you can run via standard actions in Rule Machine, for example. It's also an option in HSM, as you may have seen. But without this command available in the driver for your device, you could "fake it" with a series of repeated on/off actions in your rules (or any app).

With Hue in particular, a third issue is that they do not natively support an indefinite blink/flash. (Actually, it would be possible to install a series of rules on the Bridge via the API that can do this, but I'm not aware of any integration that does, and I just recently discovered enough about this myself to see that it would indeed be possible.) They do support a command that will make them fade up/down, basically blinking (but a slightly smoother transition), for about 30 seconds. My custom CoCoHue integration can send this command natively, but you could also do it directly to the Hue API yourself with a custom app or driver if you preferred. In my integration, this is done via the "Flash" command on Hubitat, so it would work with Rule Machine or HSM. But it still may not be exactly what you want.

I know that 'flashing' isn't an option for Hue lights connected through the Hue Bridge which is why I use the term 'blinking'. With that, I mean a series of on/off or fade up/down, repeated until some state-change, e.g. a variable changing state.

OK, so the "Flash" command in CoCoHue would do you what you want, but what that really does is set {"alert": "lselect"} on the bulb or group via the Hue API, which will make them fade up/down for about 30 seconds. Sending this command about every 30 seconds would keep the effect going indefinitely, I suppose, but it's all that Hue bulbs support natively. Beyond that, you could do like you do with any bulb and use a rule or custom app to send a series of repeated on()/off() or setLevel() commands to get the desired effect.

Speaking of custom apps, I'm aware of one but don't know if it supports HSM intrusions as a "trigger": [RELEASE] The Flasher - Flash your lights based on several triggers.