serial communication with labview tutorial loops

Why is the servo only stopping after the timeout on the vi, shouldn't it stop as messages are received / sent by the BS2?Ĥ. It works from 18 to 20, after the same gentle push to start the servo.ģ. I have also tried several timeouts for the SERIN, as this is what controls the 20ms gap between pulses for the servo.

But still it bugs me that the servo stops only after the timeout is reached on the vi. This should be mitigated by the feedback, as the main vi could detect the response and thus resend if required. On top of that, communication is fiddly, sometimes it works and sometimes it fails, even after testing several baudrates. Why isn't Main branching as intended? What am I doing wrong? I have already tried using DATA 2 to place a Comando-like 'variable' on the EEPROM, and WRITE and READ accordingly to update Comando on the Main portion of the program, but to no avail.Ģ. On the debug window, or a similar output with the echo and acknowledgement somewhere in the middle on the labview 'Read String' field (reading ~10 bytes should suffice). I ask the vi to receive four bytes after sending the message, two from the echo and two from the acknowledgement. On the Labview (v11.0 32bit) end, I had a '+' to the number I'm sending, to act as the first non-numerical symbol. Referring to the attached code, I am using Stamp_Serial_Comm.vi to communicate with the device.Īs you can see, I have included a '-' on the SEROUT that acknowledges the received instruction. I would like to know if this reluctance to start indicates a problem with the servo (which is brand new) or if it might be a timing issue with the code, or even the battery (9V Alkaline feeds board and servo through (+5)Vdd) reaching the end of its life, or if I should switch to a 1.5V 4-pack independent source for the servo. It requires a small push on the right direction to start and only then it runs fine. While both the second snippet and de DEBUG and DEBUGIN comands work fine (notice I am using port 16, the same as the debugger, for serial coms), the motor is hard to start even with the simple snippet above. The change from DO.LOOP to GOTO reflects the fact that more recently I've been trying to use the fastest code possible (as far as I know) as this is extremely important in the attached code.

I've also tried small snipets of code, such as: The code I'm working is attached, and I've tried the debuging (even changing the Latency Timer of the USB port). I'm trying to use a BS2 on a HomeWork Board (USB) to drive a Continuous Rotation Servo while controlling the direction through Labview.

Serial communication with labview tutorial loops