Other Parts Discussed in Thread: TIDA-01486
Tool/software:
I am using the EVM430-FR6047 eval board connected to a TIDA-01486 amplifier board. The amplifier board is configured to use only one pair of transducers. The hardware gains on the amplifier board are set at 5 in the transmit path and 2 in the receive path. My goal is to be able to use this system with 1 pair of transducers that clamp on to the outside of the pipe to measure water flow in the pipes.
At the moment, I have the transducers clamped on a 1-inch PVC pipe. I'm doing this right now because I have had the sytem working on this pipe with lower hardware transmit gain and I know what the ADC capture and flow waveforms should look like. Once I get this working then I intend to move the transducers to a 1-inch stainless steel pipe.
However, with the transmit hardware gain set to 5, I am getting this error: Algorithm135DToF - Shift value was greater than maxSampleShift
My ADC Capture waveform for zero water flow in the pipe looks great:
But the flow measurement waveforms are terrible for zero water flow. Below is an example in which you see that the absolute TOFs are far apart by about 6 us which makes the delta TOF about -5,000 us. For zero water flow the absolute UPS and DNS should be practically zero.
The next 2 pictures show my configuration in the USS:
I have searched in this forum for help with error 135 and the following suggestions were presented:
- increase the value USS_ALG_MAX_SAMPLE_SHIFT value in the USS_userConfigh.h - this seems to be a bandaid and may not address the real problem
- Increase the value in the envelope crossing threshold - this was suggested for somebody that had noise at the beginning of the receive burst so doesn't seem applicable in my case
- Change the value of the gain - I have done this but it doesn't help. And why would it since the ADC Capture waveform looks so good?
- Change the value of the transmit frequency - my transducers are resonant at 1 MHz so why would this work? I'll try it, but I'm not hopeful.
I'm looking for suggestions on parameter changes to stop the 135 error.
Looking forward to your response.