Campbell Scientific CR10 CR10 Measurement and Control - Page 23

cFn0 ovERvlEw emu lator (G raphTerm), telecommunications (TELCOM), a data reduction program (SPLIT), and programs to retrieve data from both generations of Campbell Scientific's Storage Modules (SMREAD and SMCOM). To participate in the programming examples (Section OVS) you must communicate with the CR10. Read Section OV3.1 if the CRlOKD is being used, Section OV3.2 if the PC208 software is being used, or Section 3.3 and Section 5 if some other computer or terminal is being used. OV3.1 CR1O KEYBOARD/DISPLAY The SC12 cable (supplied with the CR10KD) is used to connect the Keyboard/Display to the 9 pin Serial l/O port on the CR10. lf the Keyboard/Display is connected to the CR10 prior to being powered up, the "HELLO" message is displayed while the CR10 checks memory. The size of the usable system memory is then displayed (96 for 96K bytes of memory). When the CRlOKD is plugged in after the CR10 has powered up, the display is meaningless until """ is pressed to enter a mode. OV3.2 USING THE PC2O8 TERMINAL EMULATOR (GRAPHTERM) For IBM compatible computers, the PC208 software contains a terminalemulator program called GraphTerm. When using GraphTerm, the baud rate, port, and modem types are specified and stored in a file for future use. The simplest and most common intedace is the SC32A Optically lsolated RS232 Interface. The SC32A converts and optically isolates the voltages passing between the CR10 and the external terminal device. The SC12 Two Peripheral cable which comes with the SC32A is used to connect the serial l/O port of the CR10 to the 9 pin port of the SC32A labeled "Datalogger". CoRnect the "Terminal/Printer" port of the SC32A to the serial port of the computer with a straight 25 pin cable or, if the computer has a 9 pin serial port, a standard 9 to 25 pin adapter cable. To establish the communication link between the computer and the CR10, the user may either select the T option and send carriage returns as described above or select the "C" option to "Call" the station (see PC208 Operator's Manual). Once the link is active, issue the "TH" command to enter the Remote Keyboard State. OV3.3 ASCII TERMINAL OR COMPUTER WITH TERMINAL EMULATOR Devices which can be used to communicate with the CR10 include standard ASCII terminals and computers programmed td function as a terminal emulator. OV3.3.1 COMPUTER/TERMINAL REOUIREMENTS The basic requirements are: 1. There must be an asynchronous serial port to transmit and receive characters. 2. Communication protocol must be matched for the two devices. 3. The proper cable/interface must be used between the serial ports. 4. A computer must be programmed to function as a terminal. While the connection between the computer/terminal and the CR10 may be via modem (phone, RF, or short haul), the most frequently used device for a short connection is the SC32A Optically lsolated RS232 lnterface. Most computer/terminal devices require RS232 input logic levels of -5V for logic low and +5V for logic high. Logic levels from the CRl0's serial l/O port are 0V for logic low and +5V for logic high. The SC32A convefts and optically isolates the voltages passing between the CR10 and the external terminal device. The SC32A is configured as Data Communications Equipment (DCE) for direct connection to Data Terminal Equipment (DTE) which includes most computers and terminals. The SC12 Two Peripheral cable which comes with the SC32A.is used to connect the serial l/O port of the CR10 to the 9 pin port of the SC32A labeled "Datalogger". Connect the "Terminal/Printer" port of the SC32A to the serial port of the terminalwith a user supplied straight cable with the proper connectors (Campbell Scientific SC2SPS or equivalent for a 25 pin serial port configured DTE). ov-9