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Appendix F Serial Communications Overview
LiQuilaz II E and S Operations Manual
Page F-9
Troubleshooting Serial Communications
Here are some basic troubleshooting guidelines.
No Communications
Is all the cabling correct?
• Add a null-modem adaptor and see if that resolves the issue.
Is the right COM port selected in the communication settings?
• If using a USB to serial adaptor, use the Windows Device Manager to find the
correct COM port.
Are the communication settings correct? Is the software set for 9600,N,8,1?
• If the problem is with a LiQuilaz II, check the instrument’s communications setup
screen.
Is hardware flow control enabled?
• If so, disable it.
Dropped Characters or Strange Characters
Is the baud rate correct?
• Verify that hardware flow control is not enabled.
Is there a problem with the serial port on the PC?
• Bad USB to Serial adaptor drivers can cause issues.
Unexpected Characters
• If there are extra blank lines, check the <CR> and <LF> input translation.
• If characters are duplicated, half duplex mode may be enabled. Use full duplex
mode.