LocalPort Property

The TCP port in the local host where the class binds.

Syntax

 rcp.getLocalPort([callback])
 rcp.setLocalPort( localPort, [callback])

Default Value

Callback

The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).

The callback for the getLocalPort([callback]) method is defined as:

function(err, data){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'data' is the value returned by the method.

The callback for the setLocalPort([callback]) method is defined as:

function(err){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'err' has 2 properties which hold detailed information:

err.code
err.message

Remarks

The LocalPort property must be set before a connection is attempted. It instructs the class to bind to a specific port (or communication endpoint) in the local machine.

Setting it to 0 (default) enables the class to choose a port at random. The chosen port will be shown by the LocalPort property after the connection is established.

LocalPort cannot be changed once a connection is made. Any attempt to set the LocalPort property when a connection is active will generate an error.

Use this property with caution. If you supply a value, it must be an available port on the system, or an error will be returned. Furthermore, the class always attempts to bind to a secure (sub 1000) port when the value of LocalPort is the default (0). If you supply your own value, make sure the remote system is configured to allow that particular value.

This property is not available at design time.

Data Type

Integer