Program Explanation TXD and RXD

[touyi100 0]

Hi there,

I am fairly new to PLCs currently trying to connect an external serial device to the plc and trying to send an ascii string through the built in rs232 port. I called omron tech support today and they sent me a sample program. I was disconnected before I could ask some questions so if anyone could explain this basic program I would greatly appreciate it. The program starts on page 4, and is basically sending an the string <Hello> through the rs232 port. The problem is this program is based on the SCU-V1 so there are flags that are not being used in my case. 

For rung 0 they are moving the hex #0 and #3111 to the SCU port. In my case since I am using the built in rs232 do I still need to MOV the #3111? I know the default for rs232 is #0 but not sure why they are sending to both.

For rung 3 where they are sending the ascii " <" why is the destination word not stored in the data memory like the other rungs below it? Is it because this is the first string?

If someone could clarify this I would greatly appreciate it. Thank You 

 

Connecting CJ1W-SCU21_41-V1 to PC by using RS-232C.docx

[gtsuport 61]

Welcome to the forum.

Have you reviewed the instruction information in the W340 programming manual?

Omron W340 Instruction Reference Manual

Also, this download from the site may help as well

Hope this will help.