User's Manual

Shenzhen Friendcom Technology Development Co., Ltd.
23
Appendix:
Modem debugging Instruction
When the GMKS
modem is installed with the radio, users need to calibrate the data deviation.
The center frequency calibration is only necessary when the modem adopts DC coupling.
Debug wiring diagram:
Figure T1: Send the AT command by PC to activate the modem launching 01 code or PN9 code
FC-302-GMSK
VR2，Deviation adjustment(TFSK signal level)
Comprehensive tester
DC power supply
Radio
PC
(personal computer)