I have multiple DAQs (2 sets of QUAD08 & 2 sets of USB1808). To make them sync to each other, I had connect the clock signal between the master device (B0 Master) and the rest of the devices. Image below shows the connectivity of the sync connection.
One of the QUAD08 (B0 Slave) is connecting to one of the motor encoder, whereas one of the USB1808 (B0 Master) is connecting to one of the analog sensor. When I run my program to begin the data collection, all the signal are perfect are sync to each other (shown in image below). However, after run for a long period (about 2 days later), I found that the signal is drift (shown in the 2nd image below).
Signal Synced:
Signal Drift:
To have clearer picture of this, I purposely log the "Current Index" value when I execute GetStatus function to process the buffer data. Below are the observation (the index below had been converted into row index where it ranged between 0 to 200):
No. Master(USB1808) Slave(USB1808) Slave(QUAD08) Slave(QUAD08)
1 100 100 99 99
2 160 160 161 160
3 200 200 199 1
.
. After 2 days later
.
nth 130 130 150 151
nth+1 179 179 198 199
nth+2 11 11 35 35
As you can see the row index for QUAD08 had been deviated very far away from USB1808. This resulting the signal cannot be sync properly. What I observed is that the deviation is getting bigger and bigger as the DAQ is running longer. However, when i re-run my program, the signal is syncing back, but it is also drift after running for a long period.
Can help to advice how should I solve this?
Below are the the settings that I had deployed:
C# .NET
Sampling Rate: 400 Hz
Scan Option for Master = ScanOptions.Continuous | ScanOptions.Background
Scan Option for Slave = ScanOptions.Continuous | ScanOptions.Background | ScanOptions.ExtClock
Question
Ricky Ooi
Greetings,
I have multiple DAQs (2 sets of QUAD08 & 2 sets of USB1808). To make them sync to each other, I had connect the clock signal between the master device (B0 Master) and the rest of the devices. Image below shows the connectivity of the sync connection.
One of the QUAD08 (B0 Slave) is connecting to one of the motor encoder, whereas one of the USB1808 (B0 Master) is connecting to one of the analog sensor. When I run my program to begin the data collection, all the signal are perfect are sync to each other (shown in image below). However, after run for a long period (about 2 days later), I found that the signal is drift (shown in the 2nd image below).
Signal Synced:
Signal Drift:
To have clearer picture of this, I purposely log the "Current Index" value when I execute GetStatus function to process the buffer data. Below are the observation (the index below had been converted into row index where it ranged between 0 to 200):
No. Master(USB1808) Slave(USB1808) Slave(QUAD08) Slave(QUAD08)
1 100 100 99 99
2 160 160 161 160
3 200 200 199 1
.
. After 2 days later
.
nth 130 130 150 151
nth+1 179 179 198 199
nth+2 11 11 35 35
As you can see the row index for QUAD08 had been deviated very far away from USB1808. This resulting the signal cannot be sync properly. What I observed is that the deviation is getting bigger and bigger as the DAQ is running longer. However, when i re-run my program, the signal is syncing back, but it is also drift after running for a long period.
Can help to advice how should I solve this?
Below are the the settings that I had deployed:
Link to comment
Share on other sites
2 answers to this question
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now