whoever may concern, I am facing two major problems during my project.
1.) Connection RS232 to SKKCA-21:
I connected a usb to RS232 from my laptop to the SKKCA-21 Bluetooth device as pin 2(Receiver) to KC_TX, pin 3(Transmitter) to KC_RX and pin 5 to GND by using Hyperterminal. I had established the protocol 115200 bits per second, Data bits 8, none Parity, 1 Stop bits and none for Flow control according to the SKKCA - User Manual. Although the connection for my usb to RS232 which under COM3 managed to established perfectly, Hyperterminal COM5 under my bluetooth kit did not manage to detect and doesn't receive the AT-ZV ConnectionUp command.
2.) Perform AT Command:
Another connection being setup by using bluetooth under COM40 perfectly receive the signal from SKKCA through bluetooth kit.
I perfectly receive signal such as
when its connected:
AT-ZV ConnectionUp
AT-ZV -ByPassmode-
disconnected:
AT-ZV -CommandMode-
AT-ZV ConnectionDown
Reset:
AT-ZV -CommandMode-
AT-ZV BDAddress 646e6c009923
a good sign to me, However under COM40 Hyperterminal, during an instruction written such as AT-ZV ConnectionDown seem to appear as appearance instate of a command "doesn't disconnect the link" under SKKCA Hyperterminal (COM5), according to the internet reference when I input AT on my COM40, COM5 should response "OK" instead of simply repeating "AT".