DUC/DDC CH0: Frequency Shift (Hz) Error

Kurz Reido <[email protected]> Thu, 18 Dec 2025 12:09:27 -0800
Newsgroups gmane.comp.gnu.radio.general
Message-ID <CAHsmMLaxHpVVOrjMW7QWLMfgzQwCwe-7x3YB3w1ABfQAQV3QVA@mail.gmail.com>
Hello,

Not sure if this is a bug or I'm doing something wrong (probably the
latter).
I'm on ubuntu using GNU Radio 3.10.9.2 (Python 3.12.3)

I have the following blocks (all RFNoC):
RX Radio -> DDC -> DUC->TX Radio

I try to use the frequency shift on DUC or DDC and get the following error:

[RFNoC Stream Controller] Error starting stream: RfnocError: ResolveError:
Attempting to overwrite property `freq@USER:0' with a new value after it
was locked!
[ERROR] [RFNOC::GRAPH::DETAIL] 0/DDC#1: RfnocError: ResolveError:
Attempting to overwrite property `freq@USER:0' with a new value after it
was locked!
RuntimeError: RfnocError: ResolveError: Attempting to overwrite property
`freq@USER:0' with a new value after it was locked!

Please let me know what additional information you need. Thank you in
advance.


***I also have a question about why my TX/RX does not activate in this
setup. I'm trying to receive a signal, shift it with an offset, and
transmit it out as soon as possible. I'll submit that later with more
details but it's probably a config issue (btw DUC/DDC are both needed since
that's how the SEP points in FPGA image for the X410 SDR come configured).
Flowgraph launches if I just set offset to 0, but TX and RX lights remain
off.