Digi 90000566_H manual Set realport, Options Keepalive=onoff, Exclusive=onoff

	set realport
set realport
Devices	This command is supported in all Digi Connect products.
supported
Purpose	Configures and displays RealPort-related settings.
Required	For Digi Connect products with root and non-root (normal) users, the root
permissions	user can configure RealPort settings. The normal user can display
	RealPort settings.
Syntax	Configure RealPort settings
	set realport [keepalive={onoff}]
	[exclusive={onoff}]
	Display current RealPort settings
	set realport
Options	keepalive={onoff}
	Enables or disables sending of RealPort keepalives. RealPort keepalives
	are messages inside the RealPort protocol, sent approximately every 10
	seconds, to tell whoever is connected that the connection is still alive.
	RealPort keepalives are different from TCP keepalives, which are done
	at the TCP layer, and configurable. The default is “on.”
	As RealPort keepalives generate additional traffic--several bytes every
	10 seconds--this option allows you to turn them off. RealPort keepalives
	may cause issues in environments that are metered for traffic, or that do
	not require this type of mechanism. In situations such as cellular/mobile
	wireless communications, when you are paying by the byte, such
	additional traffic is undesirable when a TCP keepalive can do the same
	job, and only when the connection is idle.
	If you want to have the RealPort keepalive set to “off;” consider using a
	TCP keepalive instead. This is because if the link is not closed properly,
	you could end up with your port being “locked up” with a dead TCP
	session, which is why RealPort keepalives were implemented in the first
	place.
	exclusive={onoff}
	Enables or disables exclusive mode for RealPort connections. Exclusive
	mode allows the Digi Connect device to close an existing RealPort
	connection and establish a new one immediately upon a new connection
	request from the same IP address. This mode is useful when using
	RealPort over wide area networks, which can be unstable and where you
	are charged by the byte (such as cellular or satellite), and you do not wish
	to incur costs for keep-alive traffic. Exclusive mode allows your
	application to retain continuity when temporary, unexpected interruptions
	in network connectivity occur.
Example	#> set realport keepalive=on

Chapter 2 Command Descriptions 185