Cisco 2900

I was hooking up a few Cisco 2900 Catalyst Switches today
and ran into an issue.  Normally I take the Cisco devices DTR
line and attach to my DCD line.  This is how I monitor carrier.
I made about 20 cables for 20 Cisco switches.  3 of them were
the 2900.  I did not see carrier on any of the 2900 devices.  Every
other Cisco I saw carrier.  Is there something different about
the console ports of the 2900?

Thanks,
Chris