CJ1M CPU12 Problem (Ethernet Bandwidth?)

[mopos 0]

Hello, I'm currently making a driver in .NET. I'm in the middle of implementing TCP/FINS. All is working well until I start stressing the PLC... To illustrate: If I read the current date and time (FINS/0701) 0xFF times just using a loop to send the data over the network I usually get around 200 frames back where it should be 256! (0-255). So my question is, where do I find information about how the PLCs handle data over ethernet, does it discard frames it gets too much? Does it have limitations, etc? Thanks in advance. Morten.

[beegee 7]

Hi, can you specify the Ethernet unit you are using do you count the response frames including the encapsulation? maybe you can attach the frames you sent and received during your test. Regards

[mopos 0]

Omron SYSMAC CJ1M CPU12-ETN Well, The way I do is that I encapsulate my FINS Frame in the TCPFINS Frame (consists of 4 x 4 bytes header, length, command, error code). Then I send 256 frames because that's how many Service IDs you can have at any given time. The thing is I only get about 200 frames back when I should get 256! Morten.

[Harald_Brueck 0]

Hi, in W420 chapter 6-1-3 is specified, that ETN unit has only 192 buffers. Please do not send more than 192 frames at once. The TCP-protocol itself should handle the "alloud windows size", when the buffers are full. That is to say, you should not send anything, when the alloud windows size is 0. Harald

[mopos 0]

Sorry I jumpe the Gun. I found the same in my documentation 10 minutes later or so. thanks Harald I appreciate it.