CR10X Instruction Manual
OV-12
The simplest and most common interfaces are the SC32A Optically Isolated
RS232 Interface and the SC929 RS232 interface cable. The SC32A converts and
optically isolates the voltages passing between the CR10X and the external
terminal device, while the SC929 is usually used to temporarily connect a PC to a
remote datalogger.
The SC12 Two Peripheral Cable which comes with the SC32A is used to connect
the serial I/O port of the CR10X to the 9-pin port of the SC32A labelled
‘Datalogger’. Connect the ‘Terminal/Printer’ port of the SC32A to the serial port
of the computer with an SC25AT cable.
Establish the communication link between the computer and the CR10X as
described in the relevant software manual. Once the link is active, issue the ‘7H’
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 CR10X include standard
ASCII terminals and computers programmed to function as a terminal emulator.
Computer / Terminal Requirements
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 CR10X may be via
modem (phone, RF, or short haul), the most frequently used device for a short
connection is the SC32A Optically Isolated RS232 Interface.
Most computer/terminal devices need RS232 input logic levels of -5V for logic
low and +5V for logic high. Logic levels from the CR10X’s serial I/O port are 0V
for logic low and +5V for logic high. The SC32A converts and optically isolates
the voltages passing between the CR10X and the external terminal device. The
SC32A is configured as Data Communications Equipment (DCE) for direct con-
nection 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 I/O port of the CR10X to the 9-pin port of the SC32A labelled
‘Datalogger’. Connect the ‘Terminal/Printer’ port of the SC32A to the serial port
of the terminal with an appropriate cable (Campbell Scientific SC25 or equivalent
for a 25-pin serial port configured as DTE).
Establishing Communication with the CR10X
Communication software is available for most computers having a serial port. The
software must be capable of the following communication protocol:
1.
Configuring an asynchronous serial port for 8 data bits, 1 stop bit, no parity,
and full duplex at baud rates of 300, 1200 or 9600 baud.
2.
Transmitting characters typed on the keyboard out through the serial port.
3.
Displaying characters/data received through the computer’s serial port.
