Problem of synchronism with C-DAQ 9178 chassis with NI-9232 NI-9237

[gurzo]

Hello,

I have a cDAQ-9178 chassis with 1 NI-9232 acquiring 1 PCB IEPE accelerometer + 2 NI-9237 with a piezoresistive (bridge) accelerometer. ENDEVCO 7264B-2000 .

I have a labview16  with  drive NIDAQmx16

I want acquiring the shock signal with the same time but i can't able to do it, because the signal of two accelerometeres are not synchronized ..

I hope in uyour help.

Thank you

[mcduff]

You can probably use Channel expansion with your modules.

See

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P8XiSAK&l=en-US

mcduff

[gurzo]

hello I tried to insert the cards in the same task but I didn't solve the 
problem , because the two signals are not synchronized.
In my attached VI the cards have the same sample rate 25khz  ?

I thank you for your answer

[mcduff]

What are you measuring? Is it the same accelerometer that shows a delay through different a module? Do you have any signal conditioning present? If they are different accelerometers, are they located exactly the same distance from the source, on the same material?

You need to describe your experiment better.

One suggestion, turn off the internal excitation in VI and attach a pulse/function generator that is split between your inputs, this way it is measuring the same signal. Do you see a delay?

mcduff

[gurzo]

hello I want to make  an application to measure the amplitude of the signals of two  accelerometers:

an ICP accelerometer composed of an accelerometer  ( CTR) + signal conditioner connected to the C-DAQ1 / MOD1 / ai0 input (NI-9232) and an ENDEVCO accelerometer  Full  bridge (taratura) connected directly to input of  C-DAQ1 / MOD2 / ai0 (NI-9237).

As you suggested I tried to connect the two channels to a signal generator with sinosoidal signal amplitude 10 mVpp and frequency 100Hz but as you can see from the attached PDF the signals are not aligned

I hope my English is  understandable for you

thank you

[gurzo]

hello I want to make  an application to measure the amplitude of the signals of two  accelerometers:

an ICP accelerometer composed of an accelerometer  ( CTR) + signal conditioner connected to the C-DAQ1 / MOD1 / ai0 input (NI-9232) and an ENDEVCO accelerometer  Full  bridge (taratura) connected directly to input of  C-DAQ1 / MOD2 / ai0 (NI-9237).

As you suggested I tried to connect the two channels to a signal generator with sinosoidal signal amplitude 10 mVpp and frequency 100Hz but as you can see from the attached PDF the signals are not aligned

I hope my English is  understandable for you

thank you

[mcduff]

Are you connected directly to the inputs, or are there any signal conditioners in between?

Can you change the OnBoardClock to the clock of a specific device?

mcduff

[gurzo]

with  accelerometer CTR is connected to   cDAQ1Mod1/ai0  (NI9232)

 through a signal conditioner.

 with accelerometer tara is connected  directly  to   cDAQ1Mod2/ai0  (NI9237)

With signal generator  both channel are connected  directly .

If  i change  sampleclock witha different value than   "OnBoardClock"  value  labview

give me  an error 200414 "Requested sample clock source is invalid."
I want use  digital  edge with  "cDAQ1/PFI0" for trigger because my shock test machine  give a TTL signal 0 -5V  for synchronization.

thank you

[gurzo]

Hello,

I can't solve the problem of synchronism with C-DAQ 9178 with NI-9232 NI-9237 .

So  I want to ask you if it could be a problem of the hardware because I have seen in MAX where  NI-9232  and NI-9237  don't support any type of routing because in the attached tables the cells are empty and not green or yellow as for other devices.

Thank you

[gurzo]

Hello,

I can't solve the problem of synchronism with C-DAQ 9178 with NI-9232 NI-9237 .

So  I want to ask you if it could be a problem of the hardware because I have seen in MAX where  NI-9232  and NI-9237  don't support any type of routing because in the attached tables the cells are empty and not green or yellow as for other devices.

Thank you