Can any of the USB-3100 series devices output more than 20mA?
Three of the ten models within the USB-3100 series can precisely control 0-20 mA of current on each channel. The USB-3102/USB-3104/USB-3106 models offer 4/8/16 channels respectively. The most common application is analog control via a "4-20 mA" current loop. However, if one wishes to control current more than 20 mA, it can be done by connecting two channels in parallel. This is not commonly needed, and is not an advertised capability, but it has been tested by Application Engineering. Either of the two connection modes (grounded load with floating supply, and floating load with grounded supply) can be used. In software specify the amount of current for each channel, and the result will be the arithmetic sum of the two. Connecting more than 2 channels in parallel was not tested, but should work OK. It should be noted that the outputs of these models are fixed as single-ended (they are non-isolated, with each output referenced to PC/earth ground).
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