CTI 2572-B - Create Socket Command

CTI 2572-B / 2500C-2572-B Installation and Operation Manual 38
To send a multicast message, you need to do the following:
1. Ensure that the IP hosts you wish to process the request are configured to accept the multicast
address you are using.
2. Execute the C
REATE SOCKET command using a multicast address. This command is explained in the
following section.
3. Use the UNACKNOWLEDGED WRITE command to send a multicast message containing the data you
wish to write. See page 46 for a description of this command.
9.3. Create Socket Command
The CREATE SOCKET command provides a means for your PLC logic to refer to another network node when
sending messages. You must complete the C
REATE SOCKET command before you can send messages to another
node on the network.
The CREATE SOCKET command creates a local TCP/IP socket and associates it with the remote socket specified by
the values for IP address and port in the command block. If TCP is specified, an actual logical connection to the
remote node is attempted. If the connection cannot be established, the 2572-B will return an error code to
the PLC. If UDP is specified, the 2572-B module saves the address and port number as the default remote
socket, but no connection attempt is made. Once the C
REATE SOCKET command completes successfully, your
logic can use the Connection Number to refer to the remote socket. You can establish up to eight concurrent
connections.
Offset
Description
Hex
Decimal
0
Error Word
0000
0
1
Command Code (Create Socket)
0003
03
2
Connection Number (19221 - 19228)
3
Protocol Manager Number
0024
36
4
Startup Option Bits (see description below)
0000
0
5
Type of Service (1 = TCP, 2 = UDP/Multicast)
6 IP Address of Remote Device or Multicast
Address (High 16 bits)
7 IP Address of Remote Device or Multicast
Address- (Low 16 bits)
8
Unused (Set to 0)
0000
0
9
Remote Device - TCP/UDP Port Number
10-15
Unused (Set to 0)
0000
0
Offset 0 Error Word - Set to 0 so that any previous error codes are cleared.
Offset 1 Command Code - The Command Code of the C
REATE SOCKET command is 03.
Offset 2 Connection Number - Network Client connection numbers may range from 19221 through
19228. Any connection number within the valid range can be assigned, as long as the
number is unique. Connections can be closed and re-used, if desired. To help keep track of
the connection numbers, you may wish to assign connection numbers sequentially.