TCP/IP communication

[alberto05 1]

Hi all, I am trying to communicate with a cj1mcpu12+etn21 with tcp commands, i have allready downloaded the jay code for UDP communications and i use it for building the Fins command to send but the results are not good in my application. my pc is 101.112.123.5 the plc is 101.112.123.6 i put 9600 as port number i send this fins data: 800002010600010300000501 (model read) in the jay code that works but in my code the result is: FINS + cubes and zeros is any configuration needed before sending the command? thanks in advise Alberto

[TERdON 9]

Sounds like you're getting some form of FINS/TCP answer, just as expected if communicating via FINS/TCP. The message you say you're sending is merely a FINS command on it's own. How, exactly, are you sending it? Key points: FINS/UDP (what Jay's demo illustrates) is quite different from FINS/TCP due to the radical differences between UDP (unreliable packet transmission) and TCP (reliable stream transmission). IMHO it is easier to implement UDP transmission, but reliability is sometimes a must, so I understand your design choice. Still, make sure you don't accidentaly communicate with FINS/UDP over TCP and vice versa. You also have to add a FINS header as specified in the FINS manual. You also have to make sure that you are communicating with numbers in the correct format. FINS commands are sent as binary numbers, not ASCII (only exception as far as I know is when transmitted over Host Link - but that's more because of the properties of Host Link than FINS). Also, please refer to Omron manuals W421 and W342 to get a thorough understanding of the FINS protocol. They are both available from Omron's download centres (as well as probably on this website). Configuration beyond setting up correct adresses and (possibly) a FINS routing table shouldn´t be necessary. As you get a response, that part should be fixed already.