FPGA interface with NI 9401 and NI 9403

[Spacil]

Hi,

I am wondering about the difference between these modules when using with cRIO and FPGA interface.

As far as I think the NI 9401 has its own 2 counter/timer peripheral, so in case of using with cDAQ in can properly work as encoder input or PWN generator. But when used on FPGA all counter/timer logic can be implemented in FPGA so no peripheral is needed and thus I could use NI 9403.

What is the difference between those two modules on bare metal? The cRIO uses SPI communication to communicate between cRIO <-> modules, but what does that mean in the case of NI 9401 and NI 9403. Does NI 9401 have schema like ARM<->FPGA <--NO SPI--> |9401| Isolated buffer <-> protection <-> digital pin?

Does NI 9403 have schema like ARM<->FPGA <-- SPI --> |9403| "some kind of mux which translate SPI to DIO logic" <-> isolated buffer <-> protection <-> digital pin?

Thanks in advance for your reactions 🙂

[Antoniooh]

Hello,

Don't know where you read that NI 9401 has 2 counters, but as far as I know it has none.

NI 9401 has 8 Channels an update rate of 100 nano seconds

NI 9403 has 32 Channels an update rate of 7 micro seconds

As far as bare metal differences other than what already stated, sorry I wouldn't know.

Saludos.

[Spacil]

I concluded that it must have some peripheral due to this information in the datasheet:

[Antoniooh]

It only means that the module is compatible with counters on a Compact DAQ Chassis, older chassis have only 2 counters newer chassis come with 4 counters and you can route the digital lines form the NI 94XX to any of those counters.

Saludos.