Digi TransPort User Manual page 324

TPAD parameters
When the unit is configured for XOT or TCP socket mode, this parameter is used to specify the
IP address of the host to which the TCP/XOT connection is made. Note that the transport
protocol must be set to TCP.
Port
When making a TCP socket connection (such as the transport protocol has been set to TCP not
XoT), this parameter must be used to specify the TCP port number to use.
IP length header
When making a TCP socket connection (such as the transport protocol has been set to TCP),
setting this parameter to "On" will pre-pend the data sent to the host with a 2 byte length
header. The 2 byte length header will not be included in the length calculation. When set to
"8583 Ascii 4 byte", the IP length header will conform to the ISO 8583 format. When set to "On
Inclusive" it will pre-pend a 2 byte length header and the calculation of the length will include
the 2 bytes of the length header.
Digi TransPort User Guide 324