URGENT! serial data not being sent/receive on DVP28SV .. help?

hello everyone, can someone tell me why this program is not sending or receiving serial data?
This program reads temperature value (first two lines), initializes serial connection (lines 3-4) then does some moving of data to where it should be placed (D100 is where data to be sent is, D120 is where data to be received is) and row 9 is where the serial connection should work but it does not! i checked it using serial port monitor and i can neither send or receive to the plc .. can anyone pls help me with this? i had to cram so much about PLCs cuz this isnt my part of the project and im doing my best to make it work! any help or comments is GREATLY appreciated!

pictures 1 and 2 are after each other.

anyone please?

You got to give us a lot more information than that. Has this ever worked then stopped working? What PLC type, serial device model #, serial cable pinout, etc.. etc.. etc..

it is DVP28SV as i said in the title. im using a normal rs-232 to usb converter. didnt change anyting about the pinout.
no it didnt work yet

Ok, I get that it's a Delta PLC and you are monitoring the serial port with a serial/usb adopter. I know very little about the PLC in question, so how are you monitoring the PLC? Is it online? If so, how are you going online with it?

Typically, with serial data, it only send it once on somekind of data trigger. Have you tried to see if the PLC will receive data by sending data from your terminal program to PLC?

and, is this a school project or is there a point to what you are trying to do?

im very new too PLCs, so umm im not sure what u mean exactly about going online with it. i connect it to the PLC via the cable and make it on either via a hardware switch or via software (if thats what u mean by online).
i tried to send ine byte of data via serial port monitor and it says that its sent successfully. but the plc doesnt receive anything.
it is apparent to me that the RS instruction is not rly getting excuted...

it's a school project, and there's a point of it to send sms to control green house parameters. im done with the sms part but i have to do my partners' part now (...), but got stuck at the RS instruction. in the manual it says that this is for RS-485 but one of the instructors told me that it will work for rs-232. im beginning to doubt this, and i didnt find any rs-232 specific commands for delta dvp28sv