controls:protocols:bacnet:qna
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controls:protocols:bacnet:qna [2020/10/02 22:57] – old revision restored (2020/09/30 02:55) 5.9.70.117 | controls:protocols:bacnet:qna [2020/10/03 19:23] – old revision restored (2020/09/30 16:24) 192.99.13.75 | ||
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- | ====== Questions and Answers ====== | + | ====== |
Here are a few interesting Q&A gathered from the BACnet mailing list. | Here are a few interesting Q&A gathered from the BACnet mailing list. | ||
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===== Broadcasts ===== | ===== Broadcasts ===== | ||
+ | ??? Can devices ignore Who-Is broadcasts? | ||
+ | When sending a Who-Is broadcast, I have some devices that won't answer I-Am like I would expect them to. | ||
+ | |||
+ | - Christian Fortin | ||
+ | |||
+ | !!! | ||
+ | (…) broadcasts can and will get lost, especially when there are a lot of them. If you broadcast a Who-Is with no parameters, ALL devices have to answer, so you will get a flurry of I-Am, some of which may get dropped. | ||
+ | |||
+ | - John Hartman | ||
+ | |||
+ | !!! See the related [[http:// | ||
??? Should a BACnet/IP router answer to global broadcast messages? | ??? Should a BACnet/IP router answer to global broadcast messages? | ||
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- Coleman | - Coleman | ||
- | |||
===== max_info_frames ===== | ===== max_info_frames ===== | ||
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- John Hartman | - John Hartman | ||
+ | |||
+ | !!! | ||
+ | To question 2) | ||
+ | Devices not supporting READ-PROPERTY-MULTIPLE may significantly slow down the network. | ||
+ | The reason is: | ||
+ | - If multiple properties from the same device need to be polled by another deivce (controller or workstation) then individual READ-PROPERTY services need to be issued. | ||
+ | The amount of extra tokens used when a workstation updates it's status depends on how many properties are read from single devices. | ||
+ | |||
+ | - Christoph Zeller |
controls/protocols/bacnet/qna.txt · Last modified: 2020/10/04 07:06 by 178.151.245.174