It depends on the cameras involved.
Like the OP of this thread, I've got a bunch of Dahua starlight cams. They all have similar html get commands based on the generic Dahua HTML API. First I had to go in to each cam and setup both day and night modes according to my previous post, and set them to either "day" or "night" ('manual' condition mode), instead of auto or scheduled. Once that was done, to get BI switching between day/night modes for each camera, I selected "Custom HTML" on the PTZ tab of the camera. Then I 'edit'ed, select the desired button for day mode (I chose 'IR off', but you can use whatever you like... Preset1 for example) and enter the HTML command in the 'url' box. Likewise I added the night mode command to 'IR off'. So for my Dahuas, the custom html PTZ urls I added to BI are precisely:
Dahua Starlight Day mode (BI IR off button):
/cgi-bin/configManager.cgi?action=setConfig&VideoInMode[0].Config[0]=0
Dahua Starlight Night mode (BI IR on button):
/cgi-bin/configManager.cgi?action=setConfig&VideoInMode[0].Config[0]=1
One more if you want to switch your Dahua to 'normal' mode:
/cgi-bin/configManager.cgi?action=setConfig&VideoInMode[0].Config[0]=2
...similarly I edited the "zoom in" custom html button for my lpr cam like this:
Dahua Starlight 'refocus' (BI zoom in button):
/cgi-bin/devVideoInput.cgi?action=adjustFocus&focus=0.074129&zoom=1.0
An academic example for some camera that is zoomed almost half way in:
/cgi-bin/devVideoInput.cgi?action=adjustFocus&focus=0.074129&zoom=0.45
I hope that made sense. If you have ever played with get commands in your browser, you'll notice the first part is missing from the above lines "
http://user: password@ip". BI is smart enough to take care of the busy work for you (BI already got that info when you added the camera earlier). BI will do this for any cam, so just leave it out of your url entry.
For other cameras, many of them will have their specific get urls published somewhere online. For example these forums contain lots of discussion on get urls for Hikvision and Foscam, as well as Dahua. You'll need this info to do anything with BI custom html stuff.
You can do a lot of cool stuff with html get commands using this method in BI. With the Dahua API, you can do pretty much anything you could do from the camera webui... adjust shutter, aperture, schedules, network settings, take snapshots, download files... only thing I haven't seen done is adjusting IVS with html commands (easy enough to do manually in the webui, but it's in the API docs if anyone gets really feisty about automated IVS). Once those custom buttons are programmed, if you go to the camera's event schedule in BI, you can tell it to send any command at any time you like. This is where BI's handling of daylight savings and sunrise/sunset really comes in handy. You can even dig deeper and use scripts to fire multiple commands with the BI PTZ presets... referencing text files that are live updated by some other system/script/app. That's beyond the scope of this thread though.
Kevin