Modbus — Poll Bytes Missing Error Fixed Updated
: In Modbus Poll, go to Connection → Connection Setup . Instead of selecting "Modbus TCP/IP," select Modbus RTU over TCP/IP . 2. Physical Layer and Wiring Issues
: In half-duplex RS-485, the master might "hear" its own request, confusing its byte count. : In Modbus Poll, check the "Remove Echo" modbus poll bytes missing error fixed
[Start] │ ▼ Verify Serial Port Parameters (Baud, Parity, Stop Bits) ──► Mismatch? ──► Fix Settings │ ▼ No Mismatch Isolate the Hardware (Connect PC directly to 1 Slave with a short cable) │ ▼ Error Persists? Increase Response Timeout to 3000ms & Lower USB Latency Timer to 1ms │ ▼ Error Persists? Check Data Traffic with Communication Log (Display > Communication...) │ ▼ Analyze Rx Frame: Are bytes physically missing, or is the CRC corrupted? │ ▼ Apply Termination Resistors / Check Cable Shielding Utilizing the Modbus Poll Traffic Log : In Modbus Poll, go to Connection → Connection Setup
Here’s a structured approach to fixing errors — a common issue when the expected number of response bytes doesn’t match what’s received. Physical Layer and Wiring Issues : In half-duplex
In the Modbus Poll software, the default timeout settings might be too aggressive for your hardware, especially if you are using wireless bridges or slow cellular gateways.
Use Shielded Twisted Pair (STP) cable and ground the shield at one end only . Summary Checklist Potential Cause Reflections Add 120Ω termination resistors. Noise Use shielded cables; separate from power lines. Timing Increase Response Timeout in Modbus Poll. Framing Match Baud, Parity, and Stop Bits exactly. Hardware Replace cheap USB converters with FTDI-based ones.
Go to > Communication (or press F3). This will open the Communication Traffic window. Observe the Tx (Transmit) and Rx (Receive) frames.
“this is alas just another film that panders to the image Thompson himself tried to shirk – the reckless buffoon that is more at home on fraternity posters than library shelves. It is a missed opportunity to take the man seriously.”
This is an excellent summary on the attitude of the seeming majority of HST ‘admirers’.
It just makes me think that they read Fear and Loathing, looked up similar stories of HST’s unhinged behaviour and didn’t bother with the rest of his work.
There is such a raw, human element of Thompsons work, showing an amazing mind, sense of humour, critical thinking and an uncanny ability to have his finger on the pulse of many issues of his time.
Booze feature prominently in most of his writing and he is always flirting with ‘the edge’, but this obsession with remembering him more as Raoul Duke and less as Hunter Thompson, is a sad reflection of most ‘fans’; even if it was a self inflicted wound by Thompson himself.