MC Protocol: failed to write more than 20 device points

[tingxing 1]

Hello, I try to use MC protocol to write to D devices through the embedded TCP port . But I found only a maximum of 19 points can be successfully written. When more than 20 points write data is send, it is just overlooked by CPU - no response. this it my write data for 19 word devices (D*) - it is OK. 500000FF03FF000064000814010000D*002000001300010000177A00000000000 000000042000000000001000A0002000A0002000700010007000B this is my write data for 50 word devices (D*) - NG 500000FF03FF0000E0000814010000D*002000003200010000177A00000000000 000000042000000000001000A0002000A0002000700010007000B00010001000B0 00B0065006500C900C9006500D20191000A0029000B002B000C002D000D0030000 000000000000000000000000000000000000000000000 the communication is PC -> PLC using Microsoft Windows .Net TcpClient component. my cpu is : L26CPU-BT Could you give me any advice? Many thanks in advance! Xing

[kaare_t 155]

1. Are you sure that the devices above 19 (20-50) aren't overwritten in the PLC program? - Transfer a blank PLC program to the PLC and check again 2. Do you receive any error code from the PLC, or does it appear any error code in the PLC when debug monitoring the PLC itself? - Post any error codes

[tingxing 1]

Thank you very much for your reply. I am sure overwritten did not happen -> instead of sending once, I sent for several times, every time less than 20 words, it is OK. And there is no error code from PLC -> it seems CPU just overlooks the data packets. I asked Mitsubishi, they said there wont be any error code, or any error flag kept in CPU, it just appears nothing happened. One Mitsubishi support technician confirmed to me that this has nothing related to CPU settings, and advised me to check "TCP Maximum Segment Size". I use Windows 7, and know nothing about where to check the "TCP Maximum Segment Size" setting. Since I did no modification to my Windows network settings, I guess the default setting will not be too small to satisfy my moderate tcp datagrams. Thank you, and happy new year. Xing

[LUIS AGUIRRE 0]

Hi tingxing  i just want to know how write y 3 device poinst of one plc mitsubichi, i get an application in .NET and just can write in one register 500000FF03FF00001C000A14010000D*00000200010011 and i would like to write in three points at the same time,

im programmer and new in plc , and i would like to learn.

 

Thank you.