Communication Between NI-9149 Expansion Chassis and cRIO-9045

[ChronicTiger]

Hi,

I am using the following setup in my system:

Connect an Ethernet RIO Expansion Chassis to a Secondary Ethernet Port on a Real-Time Controller - N...

My issue is that I am inputting a known signal into a channel on the 9149 and it there is a huge delay in it showing up on my GUI.  The delay seems to grow as the programs runs longer.  Upon initial start up there is no delay but as the system runs the delays in seeing an updated value can take several minutes.  I turned off all buffering.  Does anyone have any troubleshooting tips?  Thanks in advance.

I've attached a screenshot of my data acquisition loop, its based on example code.

 

[ZYOng]

1. Instead of the while loop, try a Timed Loop.
2. What is the actual loop rate or your High Priority Loop?

[ChronicTiger]

Thanks for the advice.  I had tried a timed loop first and replaced it with a regular while loop to eliminate some variables.  Turns out it was simply the timing settings in each of the controllers for the scan engine.  I was using the defaults. I bumped up the Scan Period and the Network Publishing Period and my lag has disappeared.