Tunneled selector data not changing case structure

[GOB82]

Hello,

Hopefully a more experienced developer wouldn't mind having a look over the attached VI. The VI is for the digital control of a linear actuator , outputting over 8 lines to an external DAC. The VI has placed the output line within a case structure so that the output acts in pulses. A separate case structure exists for forward and reverse control of the linear actuator with a limit switch input (single line) provides the case structure selector.

Issue: The first issue was with latching the For/Rev case structure. During operation, a True signal from limit switch when tripped caused the actuator to change direction (good) but once the actuator moved away from the limit the signal became False, changing the direction case structure (bad). Thankfully forum member Thoric provided a method for latching and works perfectly as a stand alone VI however it does not appear to be working in the larger VI. During hightlight execution it appears the selector data from the latching function is not reaching the case structure. Would someone mind having a look at the VI, thank you.

[billko]

---

@GOB82 wrote:

Hello,

Hopefully a more experienced developer wouldn't mind having a look over the attached VI. The VI is for the digital control of a linear actuator , outputting over 8 lines to an external DAC. The VI has placed the output line within a case structure so that the output acts in pulses. A separate case structure exists for forward and reverse control of the linear actuator with a limit switch input (single line) provides the case structure selector.

Issue: The first issue was with latching the For/Rev case structure. During operation, a True signal from limit switch when tripped caused the actuator to change direction (good) but once the actuator moved away from the limit the signal became False, changing the direction case structure (bad). Thankfully forum member Thoric provided a method for latching and works perfectly as a stand alone VI however it does not appear to be working in the larger VI. During hightlight execution it appears the selector data from the latching function is not reaching the case structure. Would someone mind having a look at the VI, thank you.

---

Datflow principles dictate that the top loop won'tstart until all its inputs are satisfied.  The input to that loop cannot be satisfied until you stop the lower loop because dataflow says that you won't get an output until that loop has completed.  Try this instead.