Use U3 stream mode to read digital signal? | LabJack

Use U3 stream mode to read digital signal?

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windor_bystander's picture
Use U3 stream mode to read digital signal?

I am new to this forum. Any help is appreciated.

I intend to use U3-LV stream mode to read a 8-bit digital signal bus use 8 digital input ports. My questions are:

(1) Can I supply a external sampling clock to control the sample frequency and time? If so, what's the restriction of the external sampling clock?

(2) If only the internal sample clock can be used, the highest sample rate is 50K sample /second. For a 8-bit digital signal, the highest sample frequency would be 50K/8 = 6.25K, which seems rather low. Is my understanding correct? Based on the document, the ENOB is more than 7 bits. However, in my use case, the signal in each digital input port can only have two states, i.e., 0 or 1. It seems only 1 bit is required.  I wonder if the stream mode is the best approach to read a continuous stream of multiple-port digital signal.

LabJack Support
labjack support's picture
1.  No, for external clocking

1.  No, for external clocking you would have to move up with the T7.  Even when external clocking is supported, though, it can't exceed the normal stream speed limits (100k on the T7).

2.  You can just stream channel 193 and that will give you the state of the first 16 DI in every sample.  So you can scan the first 16 digital inputs at 50 kscans/second.