Capricorn II™ RS232C Interface User Manual Version 3.0 Copyright 1984, 1988, 1990, 2003 Columbia Weather Systems, Inc. All Rights Reserved www.columbiaweather.com Proprietary Notice: Capricorn II™ is a trademark of Columbia Weather Systems, Inc. The information and drawings contained herein are the sole property of Columbia Weather Systems, Inc. Use of this publication is reserved exclusively for customers of Columbia Weather Systems, Inc. and their personnel.
RS232C Interface Page 2 Welcome! Congratulations on your selection of the Capricorn II with RS232C Interface. The Capricorn RS232C Interface has been designed to provide a truly universal RS232Ccompatible device that gives you the flexibility to interface the weather station to your computer or peripheral. Please read the entire manual prior to installation. The diagrams below show two typical Capricorn II and Interface system configurations.
RS232C Interface Page 3 Table of Contents INTRODUCTION........................................................................................................................................... 4 SYSTEM DESCRIPTION ................................................................................................................................. 4 FEATURES...................................................................................................................................................
RS232C Interface Page 4 Introduction System Description The Capricorn II RS232C Interface is a “user-selectable” data communications interface for use with Capricorn II and Capricorn II Plus weather stations. It can operate as either DCE (Data Communication Equipment) or DTE (Data Terminal Equipment). Features Configuration Switches: Eight (8) configuration switches are provided for selecting transmission peed, character length, parity, and the output repetition rate.
RS232C Interface Page 5 Installation Instructions The RS232C Interface can be used with all RS232C compatible equipment. Your RS232C Interface includes the following items; 1. RS232C Interface Data Formatter 2. 7” (18cm) 20-conductor ribbon cable assembly 3. User Manual In addition to the above items, you will need an RS232C cable to connect the Interface to your particular device. Warning! DO NOT connect the RS232C Interface until instructed to do so.
RS232C Interface Page 6 Inside are two DIP switches marked S1 and S2. The slide switches on each DIP switch are numbered 1 through 8. Switches marked S1 select the data transmission speed, character length, parity and the output repetition length. Switches marked S2 determine how the control and communication lines are to be used. In addition, there are two pins marked RTS. This is the REQUEST TO SEND signal.
RS232C Interface Page 7 Figure 4: Sample Switch Settings S1 Set S1 positions 1 through 6 according to the information obtained for your equipment. Set S1 positions 7 and 7 according to the frequency with which you want the Capricorn II to sent data to your equipment. You can use the space below to record your switch positions.
RS232C Interface Page 8 Figure 6: Switch 2 Setting Capricorn Interface as DCE S2 S2 1 ___ 2 ___ 3 ___ 4 ___ 5 ___ 6 ___ 7 ___ 8 ___ RTS ___ Connecting the Interface Remove power from both the Capricorn II weather station and your equipment before connecting or disconnecting the cables. Unless you have the “Memory Keep Alive Battery” connected to the back of the Capricorn II, the memory will be lost each time the power is removed.
RS232C Interface Page 9 Operation Once the initial setup is complete, no user intervention should be necessary to collect or print weather data. Based on the selected repetition rate, the Capricorn II will output data through the Interface to your device in the following manner: Figure 7: Capricorn II Report Format CAPRICORN II WEATHER REPORT INSIDE TEMP XXX.X. DEGREES F OUTSIDE TEMP XXX.X. DEGREES F WIND CHILL TEMP XXX.X. DEGREES F HIGH TEMP XXX.X DEGREES F LOW TEMP XXX.X.
RS232C Interface Page 10 executed during a wait period between repetitions or after an X-OFF command (Ctrl S) to stop the data flow as described below. Be sure to send an X-ON command (Ctrl Q) to resume data flow.
RS232C Interface Page 11 Technical Information The Blue RTS Jumper If your computer or peripheral device generates and RTS (Request to Send) signal, it is necessary to connect the RTS pins with the blue jumper. Simply place the jumper so that it fits over both pins. To determine if your equipment generates an RTS signal, apply power to your equipment and use a voltage meter to determine if there is voltage between pin 4 and pin 7 of your equipment’s RS232C connector.
RS232C Interface Page 12 Figure 8: Diagram of Connections Made by S2 Operation as DTE RS232C PIN # 1 2 3 4 5 6 7 8 20 22* MNEMONIC GND TXD RXD RTS CTS DSR GND DCD DTR RI DESCRIPTION Protective Ground Transmitted Data Received Data Request to Send Clear to Send Data Set Ready Signal Ground Carrier Detect Data Terminal Ready Ring Indicator DIRECTION Both From Capricorn II To Capricorn II From Capricorn II To Capricorn II To Capricorn II Both To Capricorn II From Capricorn II To Capricorn II Operational
RS232C Interface Page 13 Says that DCE is ready to accept data from the Capricorn II. Tied to DCD in some DCE’s. The Capricorn II will not send data until DSR is active. 8 DCD Carrier Detect To Capricorn II Says that DCE has detected a carrier. The Capricorn II will not send data until DCD is active. 4 RTS Request to Send From Capricorn II When the Capricorn II is ready to transmit data, it raises RTS. RTS is dropped during the wait period between outputs and upon receipt of an X-OFF.
RS232C Interface Page 14 A typical installation would be configured as follows: RS232C Pin # DTE Capricorn II Direction 1 2 3 4 5 6 7 8 20 22 GND TXD RXD RTS CTS DSR GND DCD DTR RI GND RXD TXD Remove Jumper1 Switch Off DSR GND DCD CTS Not Monitored2 RTS DTR Both To Capricorn II From Capricorn II Not Used Not Used Both-Internal Pull-Ups Both Both-Internal Pull-Ups To Capricorn II Not Used Switch Off Switch Off 1 2 Cut trace in older units Ring Indicator is not monitored in the standard configurati
RS232C Interface Page 15 User Support Information Columbia Weather Systems, Inc. makes every attempt to ensure the Capricorn II RS232C Interface is a product of superior quality. Our documentation is detailed to provide maximum product support for the proper operation of your instrument. Limited Warranty Columbia Weather Systems, Inc.
RS232C Interface Page 16 States. If you desire a specific form of conveyance, or are located beyond these borders, you must bear the additional cost of return shipment. If you unit is not under warranty, CWS will contact you with an estimate of repair/replacement charges. If approved, your repaired/replaced unit will the returned after all charges, including parts, labor and return shipping and handling have been paid.
