Hi everyone,
I want to enable communication between a microcontroller (dsPIC33E) and the cRIO using RS-485 serial communication in the half-duplex mode. For that purpose, I use NI 9871 module.
To see what happens when I send a message via the Visa Write function, I recorded the message via an oscilloscope. Please find attached the trace. For easier referencing, let's say that the far left line denotes t=0 ms, and the time step is 1 ms.
It is clearly visible that the NI 9871 module switches to the transmit mode at t=1 ms, and that it releases, i.e. switches to the receive mode at t=10.2 ms. However, what I don't get is the delay before sending a first start bit, and after the last stop bit.
Should I implement these delays on my microcontroller as well? If yes, is there any general formula for a duration of these delays?
Thank you in advance!
Best, Marko