Ethernet Comm difficulties using EWeb module

[petemoss]

Environment: ControlLogix 1756-L61 with an EWeb card.

Trying to send a byte to a remote host via TCP.
Creating socket - success. supply instance to Open, Write, and Delete messages.
Open socket - success. (destination is being seen)
Write Socket - Error code 16#0009
Delete socket - success.

I've attached screen caps. I'm hoping I'm not chasing one of those pesky show stoppers that seem to get left out of AB documentation a little too often. Any suggestions on the error source?

Thanks in advance.

 

[Ken Roach]

You've probably seen the list of Socket Services error codes in Knowledgebase Article 34290 (TechConnect required). Error 16#0009 reads:

Invalid socket descriptor. To resolve this error, do the following:
• Make sure a valid socket instance exists.
• Make sure the message source data format and source values are
correct.
• For CREATE message make sure Type and Family is set correctly
• For UDP Read/Write - make sure that Source tag member Family is set to "2"

I'm not an expert on the Socket Services, but I think that the Socket Instance number gets reported when you create the socket. Is that the 15432 that you see in the C/I/A fields for the MSG ? Does it change each time you create a Socket ?

Is 0 the appropriate Port Number in this case, so that it's zero along with the Address, for a local IP ?

Take a step back and verify that you're trying to do an ordinary TCP connection, and describe the target device and port.

 

[petemoss]

the socket instance number is behaving as expected. i copy it from the create socket message results to the instances of the open, write, and delete as soon as it's available.

i put the address/port as used in the open message parameters in the write parameters and it did not change the results.

i am trying to perform a tcp client transaction. we have a wifi equipped target device i'm trying to write a single byte to by directing it to an ip/port. the other instructions all seem to be behaving as expected. the open fails if the device doesn't respond, so it seems to me the issue is entirely in the EWeb world.

i didn't have that list of faults, so thanks a ton for that.

 

[petemoss]

at this point i assume the second bullet is the relevant explanation.

 

[Contr_Conn]

You are writing 322 bytes, but buffer length is only 1 byte.

Source Length should be 17 in this case

See http://literature.rockwellautomation.com/idc/groups/literature/documents/at/enet-at002_-en-p.pdf page 36

 

[petemoss]

Contr_Conn, you get the bows and homage. that was it. thanks a ton amigo. that lack of attention to detail thing got me again.

 

[Contr_Conn]

You would save a lot of time by using the code from the knowledgebase.
It takes care of stupid mistakes like this.

 

[petemoss]

followup

After getting the dumb mistakes sorted out, the EWEB code is doing pretty well sending tcp commands. Pandora's box has likely just opened.