This section describes the establishment of the TCP/IP or UDP connection, the necessary data blocks and the parameterizing of the send blocks.

There are two versions of the standard send block:

• CTV: The data to be transmitted are saved as "virtual connections" in the telegram buffer. The telegram length is a result of the number and size of the data stored in the telegram buffer. Therefore, all data must be loaded, gaps in the telegram are not possible.

• CTV_P: The telegram buffer will be created by the send block with the indicated length. By means of a pointer, the address of the telegram buffer is handed over to the write blocks to store the data to be sent in the telegram buffer. Because every write block indicates an offset, not all data have to be filled in.

The following chapters only describe the request with the send block CTV_P.

Please observe the following in all connections described:

• SIMATIC TDC has to be configured as TCP/IP client, i.e. the TDC side establishes the connection, therefore in the AT connector of the send block the address stage 2 has to be configured.

• On the TDC side, the bytes have to be swapped because they are expected to be in the same order as on S7. This means all WRITE blocks have to be set on SWP=1.

• The remote port must match the setting in ibaPDA (interface TDC TCP/UDP) (default setting in ibaPDA: 4171).

• This port has to be enabled in the ibaPDA computer in the Windows firewall.

• This port cannot be allocated elsewhere.

• When creating additional conditions, please observe:

  • Always assign new channel names

  • Always issue a new local port number

  • Always use the same remote IP address

  • Always use the same remote port number