Toshiba V Series User Manual page 71

• The EN311 does not allow the user to set the subnet mask. Therefore the EN311 cannot be
used in systems that operate a subnetwork.
(3) Port number
An IP address identifies a particular node (station) on a network. However, since, on
any given node, there will be multiple applications using TCP/IP or UDP/IP to
communicate with applications on other nodes, the question of to which application
the data should be passed arises.
UDP ports have the role of acting as the point of contact between UDP and
applications that transfer data using UDP. UDP ports are managed using port
numbers. In the same manner, TCP uses TCP ports.
The combination of a port number and an IP address is called a socket. The EN311
transmits data to or from other nodes using these sockets in the computer link
protocol, the PC link protocol, and in socket interface transmission.
The range of port numbers that can be used with the EN311 is from 1024 to 65535,
for both TCP and UDP. However, note that the same port number cannot be used for
both TCP and UDP on the EN311. This is because UNIX allocates port numbers 1 to
1023 for standard services.
The following section describes the format of the parameter setup request.
(4) Parameter setup request (using the USEND_T instruction)
(a) Request command structure and error status
<Request command>
CMD
CMD+1
CMD+2
CMD+3
CMD+4
UDP PortNo: The UDP port number used by the computer link/PC link protocol
transmission.
<Error status>
STATUS
Error status examples
Error status number
-5001(16#EC77)
-5050(16#EC46)
2929(16#B71)
6F8C0904
Usage Recommendations
F
Destination EN311 module slot number
Command (16#0312)
Local IP address
UDP PortNo.
F
=0: Normal completion, ≠ 0: Error status
Command type error
Module error/Initialization in progress
Port number error
4.6 Parameter Setup Request
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0
Description
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