DS402: Increase delay to check status on homing start.#252
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af-silva merged 3 commits intocanopen-python:masterfrom Aug 16, 2021
Merged
DS402: Increase delay to check status on homing start.#252af-silva merged 3 commits intocanopen-python:masterfrom
af-silva merged 3 commits intocanopen-python:masterfrom
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The Statusword is examined immediately after setting the Controlword command to start homing. That is very likely to fail because of the round-trip time until the Statusword is actually updated from a TPDO. To work around that, the delay between each check of the Statusword should be moved before the actual comparison, and its default value increased. Introduce a new constant TIMEOUT_CHECK_HOMING to configure that with a default value of 100 ms. This replaces the previously used INTERVAL_CHECK_STATE which is only 10 ms by default. An even better solution would be to wait for the Statusword to be updated by a received PDO, but that would be much more complex.
Same problem as in the homing() method, PDO updates of the Statusword need at least one SYNC / PDO cycle duration.
Move the common code from is_homed() and homing() to a method for internal use. Add a comment why the delay is necessary and how it should possibly be replaced by an RPDO reception check. Should the latter be implemented, there will be only one place to change it.
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Note that #263 includes these changes, but goes one step further in eliminating the delays altogether when a periodic TPDO is configured (also for other cases). |
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The Statusword is examined immediately after setting the Controlword command to start homing. That is very likely to fail because of the round-trip time until the Statusword is actually updated from a TPDO. To work around that, the delay between each check of the Statusword should be moved before the actual comparison, and its default value increased.
Introduce a new constant TIMEOUT_CHECK_HOMING to configure that with a default value of 100 ms. This replaces the previously used INTERVAL_CHECK_STATE which is only 10 ms by default.
An even better solution would be to wait for the Statusword to be updated by a received PDO, but that would be much more complex.