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<p class="MsoNormal">I am only beginning to grok the etherlab stack, but I’ve got some questions about bus scanning and topology discovery.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">First, is there a reason that the user library doesn’t have a method to trigger a bus scan? There is an ioctl for it (EC_IOCTL_MASTER_RESCAN), and the ethercat tool uses that to trigger a rescan, but I don’t see any way to reach this from
the library (struct ec_master is opaque to the library user, so I can’t just call ioctl).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When the bus scan fails (under a VM this happens a lot during SII reading) there doesn’t seem to be any direct indication of this. The best indicator I can find is that the VendorId and ProductCode fields are zeroed out for a slave that
failed. Shouldn’t there be a status of some kind?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Since the bus scan takes a significant amount of time, is it possible to request a scan of only the slave(s) that failed? It doesn’t look like it, but I thought maybe I missed something.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When the master is active I understand the very low response timeout (500us). However, when the master is deactivated we aren’t guaranteed to be in real time context, so that’s a *<b>really</b>* small timeout. Isn’t it reasonable to have
a much longer timeout value for deactivated communications? On my development VM (using a USB to Ethernet adapter) I have to increase the timeout more than 1000x to avoid timeouts and failures in the bus scan. More generally, is there a reason that a user
shouldn’t be able to set the timeouts programmatically, so I can set it via config file based on deployment platform?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I see a wait queue tied to the bus scan completion, but there doesn’t appear to be a way to use it to just wait until scan completion. I’d like to be able to setup a thread that monitored the bus for changes and reacted, but it looks like
that requires polling of the scan_busy flag? At the moment it looks like the only way to reach this wait queue is via ec_master_enter_operation_phase.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When topologies change during active operation is there a way to use the slave port connectivity graph to indicate device configuration information? I know what my maximal configuration will be, and I know that dynamic connect/disconnect
will affect a specific port<->port edge. That doesn’t alter any configuration except devices sharing that edge. Tying config info to auto-inc addresses seems fragile. Has this or anything like it be discussed previously?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">-Scott Tillman<o:p></o:p></p>
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