Dear all,
I would like to do some simple frequency hopping over my USRP (x300 with UBX-160 daugherboard). To that end I wish to use the following tags:
- tx_len (defined in the length-tag field of the USRP sink). This (naturally) gives the length of a burst
-tx_freq -> used to change the centre frequency of the USRP before the first bit of every packet
-tx_time -> used to have a fixed time interval between 2 consecutive bursts
Here is my confusion:
When I add the tx_len tag to specific items, I get NO "tG"-output from gnuradio: this means that I am adding the tx_len tag correctly at the first item of every burst according to the specified burst length, correct? However, when I add the tx_freq tag to the same item that I add the tx_len tag to, I get these messages from gnuradio:
DEBUG: Received tx_freq mid-burst.
DEBUG: Received tx_freq on start of burst.
DEBUG: Received command: freq
-- Tune Request: 5793.000000 MHz
-- The RF LO does not support the requested frequency:
-- Requested LO Frequency: 5793.000000 MHz
-- RF LO Result: 5793.003663 MHz
-- Attempted to use the DSP to reach the requested frequency:
-- Desired DSP Frequency: -0.003663 MHz
-- DSP Result: -0.003663 MHz
-- Successfully tuned to 5793.000000 MHz
How can the tx_freq be received mid_burst if I place it in the same item as the tx_len tag, i.e. on the first item of a new burst? And how can it be received mid-burst AND on start of burst?