CJ protocol and SCU41

[got 0]

Hi everybody, I got a problem with a communication board CJ1W SCU 41. It works perfectly with the port number 2 that is in RS232. But the port 1 in RS485 doesn't seems to work weel. I am using a 2 wires connection on pin 1 and 2 of the DB9. i change the bit to activate port 1 instead of port 2 and nothing happen on my wiring cable..?? i made the test with 2 SCU41 different. Is there a bit to change (other than the one wich designate the port number) to communicate with the rs485 port?! Thank you Edited 2 Aug 2004 by got

[Jay Anthony 118]

Be sure to check the checkbox for Modem in the control settings.

[got 0]

all right.. it works.. thank you once again

[Jay Anthony 118]

General Notice to all new Protocol Macro users: If you are going to use RS422 or RS485 communications with Omron Protocol Macros, you need to check the Modem option in control Transmission Control like above. THis activates the tri-state switching circuit for RS485 and RS422 transmission.

[got 0]

I got another problem with my RS485 communication maybe you got a tip for me For now i was just sending command. But now i realise i nedd to receive data. So i configure a send/receive Step. But i receive what i am sending (if i disconnect the wire i still receive the same thing!) Is there something special for the reception? Thank you

[got 0]

arghh now i have nothing..!! i have try a lot of thing but i can't receive anything??!! Is there a way to visualise the receive buffer? to see if it really receive something. with an hyperterminal on a pc i have something but perhaps a bad configuration disable the reception on the CJ1 ??

[got 0]

all right... sorry for those who try to find an answer... the mistake wasn't an "omron" problem... the sequence i was waiting for wasn't the good one (i was waiting for a terminaor ETX and there was no STX...!!!) I am so stupid..!!! 2 hours loose for an ETX argh !! The first problem where i receive what i sent was just because of the full duplex mode activated. sorry

[Jay Anthony 118]

The sign of a good programmer is someone who learns to troubleshoot his own mess. Good job, got, for figuring it out. To summarize for those reading this thread, several things are important: When monitoring communications on RS485, you will see the same command that you send return as the received response. This is the nature of the beast as the physical wires for transmit and receive are tied together. What you are looking for is the response to be present after the send command on the receive line. If you are going to use RS422 or RS485 communications with Omron Protocol Macros, you will need to check the Modem option in Transmission Control. This activates the tri-state switching circuit for RS485 and RS422 transmission. For completion of the received response to be sent to the PLC, you must match every character in the reponse in the Receive message including starting and ending characters. The Trace tool is a very valuable component of CX Protocol. It is basically a built in snooper for the activity that occurs in an SCB/SCU module. To activate, you must send a command to the SCB/SCU unit to start a trace. See below:

[Guest rohit341]

Dear Jay, I am facing the same problem with SCU 41 Unit while using RS 485 Port as faced by GOT, as advised by you to check the modem option in the Transmission control settings will turn the communication ON, but can you please tell where i will find these settings i.e. in CX-Protocol or Cx-Programmer or somewhere else, please suggest as it is very critical and urgent for me.......... Thanks

[Sleepy Wombat 27]

I have not seen the dialog mentioned above for the comm's set up in CX-Prog, Or CX-Protocol... However i believe that it would relate to picking (ticking) half duplex communications in the setup for the communications for the port.

[Jay Anthony 118]

From PM this afternoon: