(contents revised Apr 2019)
This is something I have explaind to a few enthusiastic customers, but I believe it deserves its own web page.
So the answer to the question may I control several differente Seletek devices from my PC? is yes, at this moment we're limited to 2 units, but if anyone needs a 3rd one I can have that fixed in almost no time.
The key is that each software must be able to identify each controller separately. With current software versions you can mix any two controllers, whatever the model, but have to provide a way to specify each one in the configuration.
Basically, this means not to select "Any USB controller" (if both are connected via USB) as it does not identify each one separately. The less confusing option is either a specific name / IP address for network enabled controllers, and "Specific COM port" for USB connection.
Once we have a couple of suitable controllers, it is quite straightforward:
a) Open your currently working software (I'm assuming you already have a controller up and running), go to configuration, and let's be specific about the connection method:
If it's already TCP/IP, no need to modify; if however it is "Any USB controller" (default), just change it to whatever it matches your first controller.
(the option "Second Armadillo or Platypus by USB" may read "Armadillo 2" in your current software, this image is for the upcoming 4.6 version. This new text is the correct one, "Armadillo 2" is really confusing as this has nothing to do with the "Armadillo2" model)
b) Install another copy of the software to a different folder. So second instance of the software, to the, say \program files(x86)\Seletek2. Also specify a different program group, "Seletek2" is a nice option.
Notice the title of the window now reflects it's the second instance (number placed at the left to avoid confusing minimized windows). This same number will appear in any software launching for this controller, so "2 Rotator", etc.
Now go to config, and again be specific about the second controller's connection method, just as you did before.
c) That's it!
If you plan to use ASCOM, one word of warning: you can not have several ASCOM devices with same name. If you will use 2 focusers, you can have one at the MAIN port and another at the EXP port of *either* controller, but never two "Focuser Main".
If you need three Rotators, then at least one of the controllers must be a Platypus, 'cause you need one at Main, one at EXP, last one at THIRD.