We have a functioning board with a dac and when set to fullscale or zero the Ip/In will always be offset by ~3mA. If you notice below the current ranges are correct and match the general expected current as set by the Coarse DAC setting when the different is taken between In and Ip, but when the direct Ip/In current is looked at you can see it is 3mA and 17mA instead of the expected 0mA and 15mA (for the Coarse DAC=7). We have confirmed that the offset and scale factors are set to 0. What could be causing this? Is this normal? How do we fix it?
Mesurement set | Voltage Fullscale | Current Fullscale | running status | Resistance | measured voltage | volt unit | Ip/In current | current unit | sd card | Coarse DAC Setting |
78 | 0.371 | 0.01484 | DC output fullscale | 25 | 0.446 | Vp | 0.0178 | A | roan | 7 |
78 | DC output fullscale | 25 | 0.075 | Vn | 0.0030 | A | roan | 7 | ||
81 | 0.493 | 0.01972 | DC output fullscale | 25 | 0.578 | Vp | 0.0231 | A | roan | 10 |
81 | DC output fullscale | 25 | 0.085 | Vn | 0.0034 | A | roan | 10 | ||
88 | 0.430 | 0.00860 | DC output fullscale | 50 | 0.650 | Vp | 0.0130 | A | ada | 4 |
88 | DC output fullscale | 50 | 0.220 | Vn | 0.0044 | A | ada | 4 | ||
89 | 0.350 | 0.00700 | DC output fullscale | 50 | 0.560 | Vp | 0.0112 | A | ada | 3 |
89 | DC output fullscale | 50 | 0.210 | Vn | 0.0042 | A | ada | 3 |
Thank you!
Julia