Dave Smith Instruments SYNTHESIZERS

Any help will be appreciated,

I'm trying to figure how to sync  Waldorf XT Arpegiator
so it receives Midi from DSI_Evolver.
I have a midi controller pluged in the Evolver Midi in and
midi thru pluged in to XT midi in.

I'm playing Evolver sequencer so it sends
all midi Data.
When i put XT Arpegiator to Extern,
it plays once then stops. But the Arp
works when it's at any tempo, as long as it's not
EXTERN. 

All i want to do basically is to have
Evolver as the master clock so Xt's Arp
will be synced with Evolver.

Thanks for you help or suggestions,

Simon