How to read multiple quadrature encoders using data acquisition tool box?

Hello,

I want to read 3 encoders in matlab using NI USB 6343. I am using data acquisition tool box in matlab. These are the steps that i followed:

1. Daq session created

s = daq.createSession('ni');

2. Channels defined

ch = addCounterInputChannel(s, 'Dev1', [0 1 2], 'Position');

3. Read angles using

inputSingleScan(s) * 360/1000

ans =

0 0 13.3200

Now the probem is that I only receive updated value of the last encoder i.e encoder 2. First and second values are always '0'. Same is the case when I add two encoder channels. Only the last one gets updated. I have checked each encoder individually (they works fine). When I keep only encoder it always gives the required updated value on giving command inputSingleScan(s).

I have interfaced three encoders simultaneously in LabView they work fine.

Can someone identify the mistake or propose a possible approach ??

Regards