reset vcr

[ohmart]

I have a NI FBUS PCI card 2 channel, I need to clear the VCR buffer as I am limited to a maximum of 100 VCR per channel, How do I delete all previous VCR's on bot channels. Thank you

[Vince Shen]

The VCR information is stored in the MIB block of the device. You can use NI-FBUS C APIs to write zero to the VCR entries to clear the existing VCRs. Here is the procedures and pseudo-code. For more detail information about VCR structure, please refer to Foundation Fieldbus protocol specification.

• nifOpenVfd(deviceDescriptor, "MIB", &mibDescriptor);  // Open MIB block using VFD tag "MIB"

• VCR entries are the objects in MIB block. The names are VCR_STATIC_ENTRY.i . If the maximum VCR is 100, the names of VCR entries are VCR_STATIC_ENTRY.0 to VCR_STATIC_ENTRY.99. The size of each entry is 44 bytes.

        To clear existing VCR, you can write zero to all these entries.

        memset(buffer, 0, 44);

        err = nifWriteObject(mibDescriptor, "VCR_STATIC_ENTRY.i", buffer, 44);

[ohmart]

Thank you Vince for the information, however even though your instructions are clear I do not know how to launch NI-FBUS C API. Is this a software package I need to download or is it included on the CD... Appreciate a response...

To further describe my issue is, I am using a NI- FBUS PCI card with tow channels, we use this card to test our production units, each time an instrument is connected to the card a VCR is logged, with the 100 VCR limit, each channel on the NI PCI card only allows me to test 99 units. I need a way for our production techs to clear this VCR buffer or log.

We have two test benches with 2 PCI cards, Bench #1 is dead because 198 instruments have already been configured and the VCR is full, and second bench has channel #1 ful and channel 2 is also about to be full as well, I cannot connect to a new FF instrument when the limit is reached.

Best Regards

Ohmart

[Vince Shen]

NI-FBUS C API is a library (nifb.lib) which can be called through your C/C++ program. You need to use Microsoft Visual C development environment to create your application and link these APIs.

For more detail information about how to use NI-FBUS C API, please refer to NI-FBUS Hardware and Software User Manual, Page 4-12, Write Your Application. 

The manual is located at Windows Start >> Programs >> National Instruments >> NI-FBUS >> Manuals.

[ohmart]

Hello Vince,

I tried to use you code but got stuck at the 'memset' function.

I was using VB 6 and looked like this function didn't exist. 

Please help!!!!

ohmart

[Vince Shen]

The memset function in above pseudo-code just allocates a buffer array in which each element is zero. It is a function in C/C++ standard library. In VB, there is no need to do a memset. When declaring an array, all the elements will be initialized to zero by default.

NI-FBUS has VB API as well. The VB library and examples are located at <NI-FBUS installation directory>\NI-FBUS\MS Visual Basic.