After several test and trials and some discussion with the hardware supplier I could not make it work yet.
In the last email from the supplier he asked me the following:
Please let me know if your Arduino accepts only RS232 TTL level data or not?
If that's the case, then we have to provide you the pinout/p assignment of the CD-620-R to you because our CD-620-R provides signal data as RS232 level, that may cause misread of code.
I am insecure to answer this.
Anyone knows this, please?