EmbDev.net

Forum: µC & Digital Electronics MODBUS TCP help


Author: mehmet karakaya (Guest)
Posted on:
Attached files:

Rate this post
0 useful
not useful
hello dear forum,

I am trying to MODBUS TCP comunicate STM32 with Mach3

I have read the TCP documents in internet and learned
that first of all Mach3 send a TCP SYN message to the STM32

this time I send a SYN-ACK message to Mach3

after this Mach3 must send a ACK message to STM32

as you can see in the attached picture

the SYN from Mach3 and SYN-ACK from STM32 is there
(192.168.1.2) PC (192.168.1.110) STM32

however ACK from Mach3 is missing and Mach3 reports "conection timeout"

there is a warning from Wireshark yellow coloured

what does this warning say ? what shall I do next ?

thank you

Author: Moddy (Guest)
Posted on:

Rate this post
0 useful
not useful
The error means there's an acknowlede that's not corresponding to a 
message sent / received before. Thus the ack cannot be interpreted. 
Probably that's the reason why your modbos won't work.

Author: mehmet karakaya (Guest)
Posted on:
Attached files:

Rate this post
0 useful
not useful
hello dear forum,

I finally managed to respond to Mach3 MODBUS TCP SYN message

I have sent a correct SYN ACK message back to Mach3

but this time Mach3 responds with RST message - see picture

what shall I send back to Mach3 in order to finish connection process

thank you

Reply

Entering an e-mail address is optional. If you want to receive reply notifications by e-mail, please log in.

Rules — please read before posting

  • Post long source code as attachment, not in the text
  • Posting advertisements is forbidden.

Formatting options

  • [c]C code[/c]
  • [avrasm]AVR assembler code[/avrasm]
  • [code]code in other languages, ASCII drawings[/code]
  • [math]formula (LaTeX syntax)[/math]




Bild automatisch verkleinern, falls nötig