Common RS-232 Problems

Unlike GPIB, special care must be taken to ensure that RS-232 devices are correctly connected to the computer. Verifying the configuration first may save many hours of debugging time.

No Response from Instrument

Be sure the RS-232 interface is configured to match the instrument. Check the Baud Rate, Parity, Data Bits, and Stop Bits. Also, be sure you are using the correct cabling. See Appendix A - SICL Library Information for RS-232 cabling information.

If you are sending several commands at once, try sending commands one at a time either by inserting delays or by single-stepping the program.

Garbled Data Received from Instrument

Check the interface configuration. Install an interrupt handler in your program that checks for communication errors.

Data Lost During Large Transfers

Check:

• Flow control setting match
• Full/half duplex for 3-wire connections
• Cabling is correct for hardware handshaking