6 F 3 B 0 3 6 2

4.4 Parameter Setup Request

This section describes the procedure for Ethernet Port parameter setup in the Ethernet Port from a T2N user program. The Ethernet Port parameters consist of the following:

(1)Local port IP address

(2)UDP port number for computer link and PC link transmission

Here we first describe the IP address, subnet mask, and port number, which are the parameters required for TCP/IP and UDP/IP transmission.

(1)IP address

The IP address is the address that specifies a particular port when transmitted data using the IP (internet protocol). Therefore IP addresses must be set and managed so that they are not duplicated. The following presents an overview of IP addresses.

a.IP address format

An address consists of a network address and a host address. The network address is an address that specifies a particular network, and the host address is an address that specifies a particular port on that network. The same network address must be assigned to all ports on the same (i.e., any given) network.

An IP address is a 32-bit data item. IP addresses are written as the decimal values of each byte in the 32-bit datum, with the decimal values separated by dots.

Example: 11000000 00000000 00000000 00000001 192.0.0.1

IP addresses are divided into five classes, A through C, according to how many bits in the 32-bit value are used as the network address. (The networking standards also define classes D and E, but the Ethernet Port does not support them.) Figure 4.4 shows the classes A though C.

 

0

 

8

16

24

31

Class A

0

 

Network: 7

 

 

 

Host: 24 bits

 

 

 

 

 

127 values (networks)

16,777,214 values (hosts)

 

 

 

 

 

 

 

 

 

Class B

1

0

 

 

Network: 14 bits

 

Host: 16 bits

 

 

 

 

 

 

16384 values (networks)

65534 values (hosts)

 

 

 

 

 

 

 

 

 

 

Class C

1

1

 

0

 

 

Network: 21 bits

 

 

Host: 8 bits

 

 

 

 

 

 

 

 

2,097,152 values (networks)

254 values (hosts)

Figure 4.4 IP Address Class Divisions

In this system, networks with a large number of connected ports use class A addresses and networks with s small number of connected ports use class C addresses. Class B addresses are used for networks that fall between classes A and C. Expressed in decimal, the first byte of the class A through C networks will be: 0 to 127 for class A, 128 to 191 for class B, and 192 to 223 for class C.

b.IP address acquisition

Taking future uses into account, we strongly recommend acquiring an official IP address.

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Toshiba T2N instruction manual Parameter Setup Request, IP address format, IP address acquisition