I'll give you a basic example that expands a bit on what Illuminatus said about try one and then the other.

# in pseudocode no less!
get $deviceIP
ping $deviceIP or report it as not responding and exit
ssh $deviceIP
if ssh error then
    if ssh error is 'connection refused' 
    then
        telnet $deviceIP or report error and exit
        do work with telnet connection
    else 
        report error and exit
    end if
end if
do work with ssh connection
[download]

If you already know which devices use telnet and which use ssh then things get even simpler. Just try the correct protocol!

Update: Oops. I forgot the most important part.

You will not get any good responses until you can give us some clear information regarding your problem and code that demonstrates said problem.