If requested, the readout program will run a Tcl server. This is
requested via the --port option when Readout is started.
If the value of the --port is an integer, that is
taken to be the port on which the server will listen for connections.
If the value of --port is managed,
the port manager will be contacted to dynamically allocate a port
for the Readout application. The server will
listen on that port.
One use of the tcl server is to modify run variables. For example, an external program such as controlpush can be run to data on specified EPICS process variables.l