User manual

RS232C Interface Page 12
Columbia Weather Systems, Inc.
Figure 8: Diagram of Connections Made by S2
Operation as DTE
RS232C
PIN # MNEMONIC DESCRIPTION DIRECTION
1 GND Protective Ground Both
2 TXD Transmitted Data From Capricorn II
3 RXD Received Data To Capricorn II
4 RTS Request to Send From Capricorn II
5 CTS Clear to Send To Capricorn II
6 DSR Data Set Ready To Capricorn II
7 GND Signal Ground Both
8 DCD Carrier Detect To Capricorn II
20 DTR Data Terminal Ready From Capricorn II
22* RI Ring Indicator To Capricorn II
Operational Sequence:
22 RI Ring Indicator To Capricorn II
Says that the phone is ringing. Each active pulse of RI causes a 32 second timer on DTR to
be reset. *Ring Indicator is not monitored in the standard configuration of the Capricorn II
RS232C Interface.
20 DTR Data Terminal Ready From Capricorn II
Says that Capricorn II is ready to communicate. If the RI option is not installed, DTR is active
as long as DCD is active and the Capricorn II is ready to communicate. If the RI option is
installed, DTR goes active on the trailing edge of RI. If no DCD is received within 32
seconds, DTR drops. If DCD is received within 32 seconds, DTR stays high until DCD is
dropped.
6 DSR Data Set Ready To Capricorn II