From b41cf908893cc2121553e30fb282d2b52d7afabb Mon Sep 17 00:00:00 2001 From: Jonas Schumacher Date: Thu, 29 Feb 2024 10:33:44 +0100 Subject: [PATCH] Update acquisition.md --- docs/src/acquisition.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/docs/src/acquisition.md b/docs/src/acquisition.md index 63aaf058..48d92b4e 100644 --- a/docs/src/acquisition.md +++ b/docs/src/acquisition.md @@ -1,6 +1,6 @@ -# Data Acqusition +# Data Acquisition -The data acqusition of the RedPitayaDAQServer project is based on two data flows to and from the upper 128 MB of the RedPitaya memory. This memory region acts as a ring buffer for the acquired samples and can be queried by clients using SCPI commands. +The data acquisition of the RedPitayaDAQServer project is based on two data flows to and from the upper 128 MB of the RedPitaya memory. This memory region acts as a ring buffer for the acquired samples and can be queried by clients using SCPI commands. Signal acquisition within a cluster is based on a shared clock and trigger signal distributed via cables between the RedPitayas. Once triggered, all FPGAs continuously write the samples from their ADC channel to the sample ring-buffer with each clock tick. Both ADC channels on a RedPitaya are written to the buffer at the same time. The 14-bit values of the ADCs are converted to 16-bit signed integer samples and then concatenated into one 32-bit value, which is then written to the buffer. The sampling rate of the system can be adjusted by setting a decimation parameter and the decimation itself is realized with a CIC filter. @@ -43,4 +43,4 @@ At this sampling rate a single RedPitaya produces new samples at a data rate of |16|7.81|31.25|250|4.29s| |8|15.63|62.5|500|2.15s| -The table only refers to the data rate of new samples being produced. The data rate of samples being transmitted to a client can differ greatly depending on how the client queries and processes the samples and the available network bandwidth and usage. At the higher sampling rates it is recommended to have client threads that exclusively receive samples and perform any computation on samples in different threads to maximise the transmission speed, as a server can only transmit data at a rate of just above 500 Mbit/s. This exceeds the highest supported sampling rate by only a few Mbit/s and a client with frequency interruptions of its sample reception might not be able to keep up with the sampling rate. \ No newline at end of file +The table only refers to the data rate of new samples being produced. The data rate of samples being transmitted to a client can differ greatly depending on how the client queries and processes the samples and the available network bandwidth and usage. At the higher sampling rates it is recommended to have client threads that exclusively receive samples and perform any computation on samples in different threads to maximise the transmission speed, as a server can only transmit data at a rate of just above 500 Mbit/s. This exceeds the highest supported sampling rate by only a few Mbit/s and a client with frequency interruptions of its sample reception might not be able to keep up with the sampling rate.