How have you connected the FT-897 to the RRC ? If you connect from Radio-RRC com2 to the radio you need to have a Yaesu CT-62 interface between the RRC and the radio. If you do not use a real Yaesu adapter it must be one which is powered either from the Radio or from and external power. Many "pirate" CT62 is designed steal power from a PC serial ports unused pins, but the RRC do not have those pins so it will not work.
If you make a cable from the TTL jack to the radio like the description in the manual, no adapter is needed.
73 de mike