3 quadrature encoders on one 9411

[jeff_scharpf]

I'm trying to read three quadrature encoders using a 9411 in a cDAQ. In the cDAQ is a 9437 reading a load cell.

Sample rate is set to 1613 HZ, and the counters use the cDAQ/ai_clock .

Reading one encoder on DI0a/DI1a, I have no problems. As soon as I add a second encoder on DI2a/DI3a, I begin to get strange results. It's as if the position skips or jumps occasionally.

I guess before I start troubleshooting I'm wondering if there is any reason I should not be able to measure three quad encoders using the 9411.

The three encoder readings are three different tasks. Perhaps I should make them one task? These tasks are all read in a loop, 20 readings at a time, but they're reading in parallel.

Using LV2013, Win 7.

Hoping to get some advice on the code.

Jeff

[jeff_scharpf]

Sorry I was an idiot! The 9411 was missing the ground wire at pin 12!

[HVDB]

Hi,

I'm interested in your code, could you please save it in an earlier LV version, e.g. LV2011.

Thanks

[jeff_scharpf]

Sure! Keep in mind that I'm not a pro at Labview. See if this works for you. Should be in 2011