Not neccessarily, any MIDI-Clock Start or Stop signal can do it. You can route it in Ableton Live, go to Preferences (cmd;) and Link MIDI.
You can check the MIDI traffic with tools like MIDIMonitor or MidiPipe The X1800 mixer sends following MIDI signals by pressing the MIDI CLOCK button: MIDI on: From X1800 Prime Note On 16 F♯-1 127 MIDI off: From X1800 Prime Note Off 16 F♯-1 0
Ok, these are not the right messages used for start and stop but we can use MidiPipe to transform these commans into MIDI-Clock Start and Stop as a workaround.
I have done something similar for the DJM for a cueing problem I had with MidiPipe, MidiPipe can be programmed in Appletalk, here the code I wrote for the cueing problem:
on runme(message) – for Ableton Live cueing if (item 2 of message ≥ 70) and (item 2 of message ≤ 75) or (item 2 of message = 110) or (item 2 of message = 115) and (item 3 of message = 0) then set item 3 of message to 64 end if if (item 2 of message ≥ 10) and (item 2 of message ≤ 17) and (item 3 of message = 0) then set item 3 of message to 64 end if return message end runme
The only problem is that the mixer stops sending MIDI-Clock, when Ableton Live is beat-linked to MIDI-Clock (EXT top left in Ableton Live) and does not receive a MIDI-Clock it stops and cut the link to MIDI-Clock. The Mixer is sending out Active Sense, maybe this can be used to generate an continuously MIDI-Clock.
If you go to youtube and search for: Beat counter with 4 x Showtec Pixel Square 16 COB or Beat Counter with Cameo COB LED PIX BAR you will find my videos showing my beat-counter connected to Ableton Live.