As background material regarding W8NN's post - and for those who might not have seen my original message on the PW1 reflector: ===== Riding the CI-V Bus - CI-V, PW1, and Collisions
For over a month I have been studying this PW1 and CI-V issue, but have not had time to complete all the work and get the results down on paper. The completion of this study has been delayed by the failure and repair of my own PW1 and the learning curve I’ve had to climb while trying to understand what’s going on between PW1, radio, and logging software. Understand that the CI-V protocol is a bus architecture, and thus is prone to collisions. However, before condemning the CI-V protocol as inherently evil, keep in mind that another popular protocol, Ethernet, is also a bus architecture and also prone to collisions. CI-V - again like Ethernet - defines collision declaration and recovery mechanisms within its protocol. Fortunately, the CI-V and Ethernet protocols work properly; unfortunately, the PW1 does not. The issue then becomes whether today’s logging software developers can overcome the PW1’s flaws and build systems that function safely and reliably. I hope that the information discovered in this study assists them toward that end. In the mean time, I also hope that the information discovered in this study assists Icom transceiver and PW1 owners in configuring their equipment so as to minimize risks and maximize their on-air operating experience. Part I: Frequently Asked Questions www.k8ut.com/ci-v/faq.pdf 1. Why perform this study of the PW1 amplifier and the CI-V Bus? 2. I do NOT own a PW1 amplifier, but control an Icom transceiver from a computer program. Should I worry? 3. I own a PW1 amplifier, and control the amplifier and an Icom transceiver from a computer program. Should I worry? 4. I heard that the CI-V architecture is inherently broken and should be avoided at all costs. Is that true? 5. What is the primary issue with using the CI-V bus for PC-to-radio-to-PW1 communications? 6. What is likely to happen as a result of a collision on my CI-V bus? What’s the worst thing that could happen? 7. How would I know if I have a problem with my CI-V bus? 8. Is there anything I can do to reduce, or eliminate, problems with my CI-V bus? 9. What products were involved in this CI-V bus study? 10. Which programs are better at avoiding, or eliminating, problems with the CI-V bus? 11. Did theories and opinions about the PW1 and CI-V bus change much from the beginning of the study to the end of the study? 12. Could I duplicate K8UT’s tests at my QTH? 13. Will the packet logs make any sense to me? 14. Who assisted K8UT with the development of this material? Part II: PW1 and CI-V Details www.k8ut.com/ci-v/details.pdf 1. PW1 DEVICE ADDRESS 2. RADIO TO COMPUTER COMMUNICATION 3. RADIO TO PW1 COMMUNICATION 4. TRANSCEIVE = ON or OFF? 5. PW1 POLLING METHODS 6. PW1 DESIGN FLAWS 7. DISCLAIMERS ===== -larry K8UT ______________________________________________________________ Dx4win mailing list Home: http://mailman.qth.net/mailman/listinfo/dx4win Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Dx4win@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
