Hi,

I'm trying to use digital channels 5D, 6D, 7D and 8D to monitoring digital status like I usually do with 1D, 2D, 3D, 4D. The channels from 1D to 4D work correctly but the channels from 5D to 8D don't work at all: they return digital status 0 (zero) with open and close circuit.

All the channels have the same command line so I don't understand why they do not work. There something that I have to modify? Some difference between the firsts four digital channels and the others four that I have to know?

Good morning Dumnall,

Yes digital input 5 to 8 have different to input 1 to 4. Digital inputs 1 to 4 are pulled high by an internal Voltage so when you close a switch you will see the input go from High to Low. The switch in known as a passive device.

Digital 5 to 8 are designed to be driven High or Low by a active device. This allows us to do things like read SDI-12 devices and attach the CEM20. If you want to use passive with inputs 5 to 8 then you will have to have it supply the power to pull the input high.

Cheers,
Roger

Very thanks! Now all the channels work correctly.

Cheers,
Dumnall