Hi,
I have problems with the NI 9871 RS422 serial module. There is a device which has some switches on itself. device sends switches states information as a 72 byte hex character using RS422 protocol and it repeats the states information every second. Bsud rate is 115200. if there occur a state changes in switches device also send 8 byte data. I want to take this information with the NI 9871 RS422 module.
VISA Read has a byte count input and I dont know what should i prefer for the byte count. device manual says device has 64B FIFO buffer. but i can write for byte count input much more. for ex. 100, 1000 i can write this values. what is the meaning of this byte count actually. And what should i do for the RS422 read vi. should i set byte count 1 and then take all the bytes one by one? if i do that can be a problem for the speed of reading correct data. because i should use array function for the incoming data.
thanks in advance.