It looks like there is a tier/cascading option for these units. Have a look on page 31: [URL] Let me know if this what you were looking for.
We Have dell servers P.E R730 &R720 connected to the KMM by KVM Switch Model 1081 AD And We bought 5 Dell servers P.E R740 and KVM Model DAV 2108 My Question is how can we connect the new KVM DAV2108 and the old KVM 1081AD Together With The KMM To work all servers in a single KMM  
Connecting two KVM in one kmm