When you run pmode on a cluster of workers, you are running a job that is much like any other communicating job, except it is interactive. The cluster can be heterogeneous, but with certain limitations described at http://www.mathworks.com/products/parallel-computing/requirements.html; carefully locate your scheduler on that page and note that pmode sessions run as jobs described as "parallel applications that use inter-worker communication."
Many of the job's properties are determined by the cluster profile. For more details about creating and using profilies, see Clusters and Cluster Profiles.
The general form of the command to start a pmode session is
pmode start <profile-name> <num-workers>
where <profile-name> is the name of the cluster prifile you want to use, and <num-workers> is the number of workers you want to run the pmode job on. If <num-workers> is omitted, the number of workers is determined by the profile. Coordinate with your system administrator when creating or using a profile.
If you omit <profile-name>, pmode uses the default profile (see the parallel.defaultClusterProfile reference page).
For details on all the command options, see the pmode reference page.