# Uavcan::Subscriber subscribes and starts successfully, but cannot enter its corresponding callback function

**URL:** <https://forum.opencyphal.org/t/uavcan-subscriber-subscribes-and-starts-successfully-but-cannot-enter-its-corresponding-callback-function/299>\
**Category:** LibCyphal\
**Created:** [December 17, 2018, 9:05am UTC](https://forum.opencyphal.org/t/uavcan-subscriber-subscribes-and-starts-successfully-but-cannot-enter-its-corresponding-callback-function/299 "2018-12-17T09:05:08Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![zhpg](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/zhpg/32/85_2.png) [@zhpg](https://forum.opencyphal.org/u/zhpg)\
**Post date:** [December 17, 2018, 9:05am UTC](https://forum.opencyphal.org/t/uavcan-subscriber-subscribes-and-starts-successfully-but-cannot-enter-its-corresponding-callback-function/299/1 "2018-12-17T09:05:08Z")

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Hello everyone, I used the Release 2.0 version of the zubax\_gnss project, which works very well. I recently saw the latest master version and tried to use it. I found that one problem is that my program can be assigned nodes. , can also continuously send node status information, indicating that the hardware is normal, but can not enter my custom callback function, what is the reason for this?

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**Author:** ![pavel.kirienko](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/pavel.kirienko/32/9_2.png) [@pavel.kirienko](https://forum.opencyphal.org/u/pavel.kirienko)\
**Post date:** [December 17, 2018, 9:09am UTC](https://forum.opencyphal.org/t/uavcan-subscriber-subscribes-and-starts-successfully-but-cannot-enter-its-corresponding-callback-function/299/2 "2018-12-17T09:09:22Z")

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I am not sure I fully understand the question. Can you post your code, please?

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**Author:** ![zhpg](https://forum.opencyphal.org/user_avatar/forum.opencyphal.org/zhpg/32/85_2.png) [@zhpg](https://forum.opencyphal.org/u/zhpg)\
**Post date:** [December 17, 2018, 5:10pm UTC](https://forum.opencyphal.org/t/uavcan-subscriber-subscribes-and-starts-successfully-but-cannot-enter-its-corresponding-callback-function/299/3 "2018-12-17T17:10:20Z")

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Thanks Pavel for answering my question. I found some differences in the init function in the zubax\_gnss/firmware/src/node.cpp file. The master version has a configureCanAcanceanceFilters configuration filter function. I temporarily mask the filter configuration. I can enter my custom callback function; I will study your filter code in detail later.