Issues regarding Output Configuration of Boolean Array To Number

[okidoki21]

Hi,

I am want to transfer data from FPGA target to host using DMA FIFO. The datatype of DMA FIFO is set to U32. I have been following the steps given on this page (https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P8wdSAC&l=sv-SE&OpenDocument=) while performing this task. On the FPGA side, the analog voltage is acquired using NI-9229 module. 'Loop Time 1' and 'Loop Time 2' can be integer values. I am taking them to be equal to 20 and 200000, respectively. 

I am encountering an issue in Output Configuration Properties of the 'Boolean Array to Number' on the Host side. As shown below, I am not getting an option to change the representation to fixed-point and fill in the Fixed-Point Configuration according to the properties of the fixed point data type on the FPGA.

Is there something wrong with my code?

Kind Regards

[ZYOng]

You are missing while loops on both FPGA and host VI. Hence your program will not run continuously.

I would recommend you refer to shipping examples. Go to Help >> Find Examples >> Hardware Input and Output >> CompactRIO >> Module Specific IO >> Analog Input >> NI 9229 Getting Started

[GerdW]

Hi okidoki,

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@okidoki21 wrote:

Is there something wrong with my code?

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Yes.

• Why do you need to convert to a boolean array in the first place?
• Why not convert the U32 to FXP using the ToFXP function?
• Why don't you use FXP for the FIFO datatype?
• Why do you need to convert your FXP readings to boolean array to U32 in the FPGA?
• What is the FXP configuration in the FPGA? (You also missed to attach your project file so we don't know all the target-specific settings!)

[okidoki21]

Hi,

Thank you for the reply.

I can define the FIFO with FXP datatype (word length of 24 bits and integer word length of 7 bits), so as to match the datatype of NI 9229 module. However, I also want to transfer the loop time (value upto 20000) using the same DMA FIFO. Loop time changes with the iterations, that is why I want to save it along with the acquired signals using NI 9229.

I am struggling to find a optimal solution to do so. So, as per guidelines here, I was trying to convert all the FXP datatype to U32 before inputing it into DMA FIFO 'Debug' with datatype defined as U32. On the host side, I then want to convert the U32 data back to FXP datatype.

Kind Regards

[GerdW · Accepted solution]

Hi okidoki,

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@okidoki21 wrote:

I can define the FIFO with FXP datatype (word length of 24 bits and integer word length of 7 bits), so as to match the datatype of NI 9229 module. However, I also want to transfer the loop time (value upto 20000) using the same DMA FIFO. Loop time changes with the iterations, that is why I want to save it along with the acquired signals using NI 9229.

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You could scale down the integer values (upto 20000) by 512 to fit into the range of your FXP data…