cd27c54b_DB9_Pinout__Signal_Name
[Pin] 9 [SIG.] RI [DTE (PC)] in [Signal Name] 
Ring Indicator
D a t a C a r r i e r D e t e c t
R e c e i v e D a t a
T r a n s m i t D a t a
D a t a T e r m i n a l R e a d y
S i g n a l G r o u n d
D a t a S e t R e a d y
R e q u e s t t o S e n d
C l e a r t o S e n d
R i n g I n d i c a t o r
DB9 Pinout
Signal Name