Measurement Computing USB-2416-4AO, Руководство пользователя

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22
Chapter 5
Specifications
All specifications are subject to change without notice.
Typical for 25 °C unless otherwise specified.
All specifications apply to all temperature and voltage input channels unless otherwise specified.
Specifications in italic text are guaranteed by design.
Analog input
Table 1. General analog input specifications
Parameter Conditions Specification
A/D converter type ADS1256, 24-bit Sigma Delta
A/D data rates 3750 samples per second (S/s), 2000 S/s, 1000 S/s, 500 S/s, 100 S/s,
60 S/s, 50 S/s, 25 S/s, 10 S/s, 5 S/s, 2.5 S/s
Throughput 
Single channel: 2.5 Hz to 1102.94 Hz, software selectable

Multiple channels: 0.16 Hz to 1102.94 Hz, software selectable
See Table 18 and Table 19 for details.
Number of channels Up to 32 channels individually software-configurable as single-
ended or differential
Thermocouples require differential mode. For each channel
configured as differential, you essentially lose one single-ended
channel. You can add channels by connecting to an AI-EXP32.
Input isolation 500 VDC minimum between field wiring and USB interface
Channel configurations Temperature sensor input, software programmable to match sensor
type
Voltage input
Input voltage range Thermocouple mode ±0.078125 V
Voltage mode (Note 1) ±20 V, ±10 V, ±5 V, ±2.5 V, ±1.25 V, ±0.625 V, ±0.3125 V,
±0.15625 V, ±0.078125 V, software-configurable
Absolute maximum
input voltage CxH-CxL relative to
GND

±30 V maximum (power on)

±10 V maximum (power off)
Input impedance

2 G
Ω (power on)

390Ω (power off)
Input leakage current ±10.6 nA
Input capacitance 590 pf
Maximum working
voltage (
common mode) Voltage mode: ±20 V
range ±20.01 V maximum
Voltage mode: all other
voltage input ranges ±10.25 V maximum
Common mode
rejection ratio (Note 1) Thermocouple mode,
(f
IN
= 60 Hz)
110 dB
Voltage mode,(f
IN
=
60 Hz, all input ranges)
90 dB
ADC resolution 24 bits
Crosstalk Adjacent channels 100 dB
Input coupling DC
Channel gain queue Up to 64 elements Software-configurable channel and range
Warm-up time 45 minutes minimum
Open thermocouple
detect Automatically enabled when the channel is configured for a
thermocouple sensor.
CJC sensor accuracy 15 °C to 35 °C ±0.15 °C typical
0 °C to 55 °C ±0.5 °C maximum