Sending commands(ASCI characters) via RS-232

[bluepoint4]

Hi, I'm having trouble with sending serial (ASCI characters) commands via RS-232. 

I'm using Bluepoint4 uv lamp (Hoenle, co), and I connect Bluepoint4 to PC through a RS-232 to USB connector since our PC does not have RS-232 port.

I have been trying to send command with 2 example codes that I got from this forum, but both of them did not work for me.. 

The 1st example code is a terminal just like Hyperterminal, and 2nd code is pretty much same with 1st on (from my understanding)..

I don't know where to start... Thank you for reading through.. 

[RTSLVU]

Most serial communication problems can be solved by watching this video: VIWeek 2020/Proper way to communicate over serial

[kartik.azista]

You just need to concatenate : with your command and carriage return constant as shown below