Stanford Research Systems RGA100, Operating Manual And Programming Reference

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6-6 RS232 Interface
SRS Residual Gas Analyzer
RS232 Interface
The RS232 interface connector of the RGA is a standard 9 pin, type D, female connector
configured as a
DCE (transmit on pin 3, receive on pin 2) with full RTS/CTS
handshaking enabled. The CTS signal (pin 8) is an output indicating that the RGA is
ready, while the RTS signal (pin 7) is an input that is used by the host computer to
control the RGA’’s data transmission.
The communication parameters are fixed at: 28,800 baud rate, 8 databits, no parity,
1 stop bit .
Cable connection: Use a straight through RS232 cable with 9-pin, type D connectors to
connect the computer (usually DTE) to the ECU. The DB9 to DB25 adapter (provided
with the unit) will be needed if the computer has a 25 pin Type D connector.
Important : If you use your own RS232 cable check the connectors to make sure all the
necessary handshaking lines are connected correctly. If a USB-to-Serial or Ethernet-to-
serial adapter is used, make sure all required drivers are installed in the computer before
communication is attempted.
LED Indicators
To assist in programming, the RGA has two status LED’’s on the rear panel of the ECU
box.
RS232 LED: RS232 Activity indicator that flashes whenever a character is received or
transmitted over RS232.
Error LED: The Error LED flashes on/off a couple times when an error, such as an
illegal command or parameter, has been detected.