Move the serial cable way from power cables, monitors, or other potential noise sources. You may be experiencing noise on your serial line. Refer to the article: Should I Use Null Modem or Straight Through Serial Cables?į. Try another serial cable and check your device manual to determine if a null modem or straight through cable is required. You may have a bad serial cable or the wrong type of serial cable. Check to make sure your cables are securely plugged in.Į. Note: You can change these settings programmatically during run-time as seen in the example above, or in NI-MAX as in the example below.ĭ. The easiest way to check the configuration is by tracing the received signal with an oscilloscope. Verify that the VISA Resource Name, Baud rate, Data bits, Parity, and Stop bits all match the settings of your device under the port settings tab. To solve this issue, open NI Measurement & Automation Explorer (NI MAX) and select your serial port under Devices and Interfaces. Your serial port and device may be configured to use different settings. You may be closing the VISA Resource before the Read/Write task is complete.Ĭ. Your block diagram should appear as shown below:ī. Reading after this sequence should work correctly. Then, by using a VISA Flush I/O Buffer VI, you can clear any invalid data in the buffer. By putting a delay (approximately 10-100 ms) after the VISA Configure Serial Port VI, you allow the serial port enough time to configure itself. The port may not have completely finished its configuration by the time the first character is received off of that port. A framing error occurs when a byte of data is received, but it is not in the format expected. This kind of error may occur for several reasons:Ī. Each byte has a specific format with a start bit, data bits, parity, and stop bits. Serial data is transferred one byte at a time.
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