CTI 2572-A, Installation And Operation Manual

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CTI 2572-A Installation and Operation Guide V1.3 35
5.5. Memory Transfer Commands
Memory Transfer commands are designed to provide a device independent method of transferring
data words. For SIMATIC® 505 PLCs, the memory transfer commands provide a simple way to
transfer V memory between the local PLC and another PLC (or suitably programmed computer) on
the network. These commands access only the first 64K bytes of V memory. Before using the
Memory Transfer commands you must have successfully completed a C
REATE
S
OCKET
command.
Word Transfer - Write
This function reads the contents of a designated area of V memory in the local PLC and writes the
values in a specified area of memory in another PLC. You can specify the starting memory addresses
on both the local and remote PLCs and the number of words to be transferred (up to 256 words).
When the command is triggered, the 2572-A reads the local V memory and sends a request message
to the remote PLC. When the response is returned from the remote PLC, the 2572-A verifies that the
message was properly processed. If not, the 2572-A places the error code in the command block and
raises the applicable error bit. The following command block is used for the W
RITE
command.
Offset Description Hex Decimal
0 Error Word
0000 0
1 Command Code (Write)
0201 513
2 Connection Number (19221 - 19228)
3 Source: Starting V Memory Address in the Local PLC
4 Number of Words to Transfer (1-256)
5 Destination: Starting V Memory Address in Remote PLC
6 Command Timeout in seconds (0 = Use Default) 0000 0
7 - 9 Unused (Set to 0) 0000 0
10 IP Address of Remote Device - High 16 bits
(UDP Only: IP Address Location bit in the Create Socket
command must be set to 1)
11 IP Address of Remote Device - Low 16 bits
(UDP Only: IP Address Location bit in the Create Socket
command must be set to 1)
12 UDP Port Number of Remote Device
(UDP Only: IP Address Location bit must be set to 1)
13 - 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 is 513 decimal (or 0201 hexadecimal).
Offset 2 Connection Number - You can specify any connection number that has been previously
established in a C
REATE
S
OCKET
command block.
Offset 3 Source - The starting address of V memory which contains the values you want to transfer.
The address is 1 relative.
Offset 4 Number of Words - This indicates the number of words you want to transfer.