From the X1 Manual. I just looked up stuff on Midi Sync:
To use MIDI Sync with SONAR as the master
1. Configure your external MIDI devices to receive MIDI Sync.
2. Go to Edit > Preferences > Project - MIDI.
3. Check the Transmit MIDI Start/Continue/Stop/Clock box.
4. For most applications, check the Transmit MIDI Song Position Pointer box.
5. If you are using a drum machine to play patterns or loops, check the Use Start, Never Continu
option and disable the Transmit MIDI Song Position Pointer option.
6. In the MIDI Sync Output Ports field, check off the output ports that you want to send the sync
signal out of.
7. Click OK.
From now on, the transport controls in SONAR control playback on the external MIDI devices.