Large-size NOP Command

[arnoldhsiao]

In NOP Test of ODVA CIP Protocol Conference Test, NOP commands with data lengths of 0, 2000, and 65511 must be received consecutively. I keep receiving the following error messages and cannot pass the NOP test.
1> *** Send() error for NOP.
2> *** Large size Encapsulation Command caused the DUT to close the TCP connection. See requirement in Vol 2 section 2-3.3.

How should I modify OpENer to pass the NOP test?

[lunar-me]

OpENer's default TCP receive buffer is only 512 bytes (OPENER_ETHERNET_BUFFER_SIZE defaults to 512 in CMakeLists.txt). The TCP handler reads the encapsulation header, then drops any packet whose data_size exceeds PC_OPENER_ETHERNET_BUFFER_SIZE - 4. A NOP command with a 65511-byte payload therefore cannot be received with the default build;

I reckon, you need to increase OPENER_ETHERNET_BUFFER_SIZE at CMake configure time to at least encapsulation header length + 65511 bytes. I'd set to 65535 bytes at a first try.