Campbell SC32A, Справочное руководство

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1
SC32A Optically Isolated RS232 Interface
The SC32A interfaces an RS232 peripheral, commonly a computer or printer, to the serial
I/O port of a Campbell Scientific datalogger. The SC12 cable supplied is used to connect the
datalogger to the 9-pin port of the SC32A. Connection to the serial port of a PC is made with
an RS232 cable such as the Campbell Scientific SC25 or SC25AT.
Refer to this manual if you have difficulty communicating with your PC or if you intend to use
the SC32A with anything other than a PC.
1. Function
The functions of the SC32A are:
1. To convert datalogger logic levels to RS232 logic levels.
2. To optically isolate the datalogger and the RS232 peripheral. Optical
isolation separates the SC32A into a datalogger section and an RS232
section. Signals entering from either side are electrically independent,
protecting against ground loops, normal static discharge and noise.
3. To block the transmission of synchronous CR10 data to the RS232
peripheral. This function is enabled by the installation of an internal jumper.
SC32As with serial numbers less than 1500 were shipped with the jumper in the
blocking position (two posts connected). All other SC32As have the jumper on
one post only, in the passing position.
When used with a CR10 Measurement and Control Module, the correct SC32A
jumper position depends on the application. For all other Campbell Scientific
dataloggers, the jumper has little effect and could be removed (see Section 5).
2. Specifications
Operating temperature: -25
o
C to +50
o
C
Power: Powered by host devices (see Section 4)
Ports: 25-pin female; configured as DCE
9-pin male; connects to datalogger via SC12 cable (included)
Size/Weight: 130 x 60 x 25mm, 0.1kg
3. Connector Descriptions
3.1 25-Pin
The SC32A 25-pin female port is configured as Data Communications Equipment
(DCE) for direct cable connection to Data Terminal Equipment (DTE). Most
terminals, computers and printers are configured as DTE. For connection to DCE
devices such as modems and some computers, a null modem cable is required (see
section 5).