The pack needs to be 

my $status = pack( 'H[12]', 'ca00010000fe' );

[download]
I figured it out by printing $status to a file and then using a hex editor (and reading pack ;-).

In reply to Re: Sending and reading hex commands on a Win32 serial port by hipowls
in thread Sending and reading hex commands on a Win32 serial port by c4onastick

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