Spectrum Controls 1746sc-NI8u - Manual (Page 43)

Chapter 3: Things To Consider Before Using Your Module 31
a mid voltage input path, and a high voltage input path. The following table
correlates input type to input path.
Input Type Input Path
4 to 20mA Mid
0 to 20mA Mid
± 50mV Low
± 100mV Low
± 500mV Mid
± 2V Mid
0 to 5V, 1-5V High
± 10V, 0-10V High
All Thermocouple Types Low
Pt 385 RTD, 100 Ω Low
Pt 385 RTD, 200 Ω, 500 Ω , 1000 Ω Mid
Pt 385 RTD, 100 Ω Low
Pt 385 RTD, 200 Ω, 500 Ω , 1000 Ω Mid
Cu 426 RTD, 10 Ω Low
Ni 618 RTD, 120 Ω Low
Ni 672 RTD, 120 Ω Low
CJC Low
3000 Ω Resistance Mid
Each input path supports four different filter frequencies: 10Hz,
50Hz, 60Hz and 250Hz. The following table indicates auto-
calibration time based on the input path, and the selected filter
frequency.
Input Path 250Hz Filter 60Hz Filter 50Hz Filter 10Hz Filter
Low 181mS 384mS 435mS 1.85S
Mid 181mS 384mS 435mS 1.85S
High 96mS 208mS 238mS 1.03S
CJC sensors are acquired through the low voltage input path at
60Hz, to maximize the trade-offs between resolution and update rate.
Once every two minutes, the module calibrates one of the input path and
filter combinations on successive scans until all input path and filter
combinations that are used have been calibrated. During auto-calibration,
the module scan time will increase by the auto-calibration time.
Auto-calibration can be disabled by placing a one in any enabled channel’s
auto-cal disable bit.