CLIMET INSTRUMENTS CI-154, Руководство пользователя, Страница: 53 / 98

CI-154 User’s Manual
Page 43
3.2 RS-232 interface
The RS-232 interface conforms to the (Electronic Industries Alliance) EIA standard
as a DCE device with a 9-pin ‘D’ connector. The initial BAUD (bits per second) rate is
9600 BAUD and can be changed to 115200 BAUD. The DCD, DSR, and CTS lines are
held in the high state, as the serial port is interrupt driven and is always ready to
receive. Serial data settings are: 8 data bits, 1 stop bit, no parity
DB9 RS232 pinout
Pin Counter Computer Computer Signal Description
1 Active Hi DCD Data Carrier Detect (In)
2 TxD RxD Receive Data (In)
3 RxD TxD Transmit Data (Out)
4 N.C. DTR Data Terminal Ready (Out)
5 GND GND Ground
6 Active Hi DSR Data Set Ready (In)
7 N.C. RTS Request To Send (Out)
8 Active Hi CTS Clear To Send (In)
9 5V RI Ring Indicator (In)
An off the shelf DB9 straight through (opposite gender on each end) cable will
connect the particle counter to a PC serial port.
Pin 9 of the RS-232 connector pr5 VDC at 400 mA. This enables a bar-code
scanner accessory to be connected and powered directly by the particle counter.
Contact Climet for more information.
3.2.1 Controlling the CI-154 through the RS-232
interface
The CI-154 can be programmed and operated by means of the RS-232 port. The
CI-154 responds to external commands that are sent in ASCII alphanumeric
characters. The table in section 3.3 lists the ASCII characters and their functions.
Commands start with an ASCII character; depending on the command type, they
may also be followed with a parameter field, designated below as n or nn.
To invoke a function, send an ASCII letter and then a carriage return to execute the
function. Multiple commands, up to 50 characters in length, may be sent with only
one carriage return as the last character. The receive buffer is 50 characters long—if
overfilled, it will ignore all commands except the tilde [~] character. The tilde
character is used to clear the receive buffer and should be sent at the beginning of
each ASCII command string. If a command is sent with an invalid n or nn parameter
field, the command will not execute.
All data transmissions from the CI-154 are terminated with a bell character (07hex).
The echo feature is used to send back the command characters as verification that
they have been received. When in doubt, hook up a dumb terminal, or a PC running
a terminal emulator program, and try each command to test the instrument.