Chapter 5 Specifications; Analog Input; Channel Configurations - Measurement Computing USB-5200 Series User Manual

Specifications
All specifications are subject to change without notice.
Typical for 25 °C unless otherwise specified.
Specifications in italic text are guaranteed by design.

Analog input

Parameter
A/D converters
Number of channels
Input isolation
Channel configuration
Differential input voltage
range for the various sensor
categories
Absolute maximum input
voltage
Input impedance
Input leakage current
Normal mode rejection ratio
Common mode rejection
Ratio
Resolution
No missing codes
Input coupling
Warm-up time
Open thermocouple detect
CJC sensor accuracy

Channel configurations

Internally, the device has four, dual-channel, fully differential A/Ds providing a total of eight differential
channels. The analog input channels are therefore configured in four channel pairs with CH0/CH1 sensor
inputs, CH2/CH3 sensor inputs, CH4/CH5 sensor inputs, and CH6/CH7 sensor inputs paired together. This
channel-pairing requires the analog input channel pairs be configured to monitor the same category of
temperature sensor. Mixing different sensor types of the same category (such as a type J thermocouple on
channel 0 and a type T thermocouple on channel 1) is valid.
Channel configuration information is stored in the EEPROM of the isolated microcontroller by the firmware
whenever any item is modified. Modification is performed by commands issued over USB from an external
application, and the configuration is made non-volatile through the use of the EEPROM.
Table 1. Generic analog input specifications
Conditions
Thermocouple
RTD
Thermistor
Semiconductor sensor
±C0x through ±C7x relative to GND
(pins 9, 19, 28, 38)
Open thermocouple detect disabled
Open thermocouple detect enabled
fIN = 60 Hz
fIN=50 Hz/60 Hz
15 °C to 35 °C
0 °C to 70 °C
22
Specification
Four dual 24-bit, Sigma-Delta type
8 differential
500 VDC minimum between field wiring and USB
interface
Software programmable to match sensor type
±0.080 V
0 V to 0.5 V
0 V to 2 V
0 V to 2.5 V
±25 V power on, ±40 V power off
5 GΩ, min
30 nA max
105 nA max
90 dB min
100 dB min
24 bits
24 bits
DC
30 minutes min
Automatically enabled when the channel pair is
configured for thermocouple sensor.
The maximum open detection time is 3 seconds.
±0.25 °C typ,±0.5 °C max
–1.0 °C to +0.5 °C max
Chapter 5