6
Chapter 1
Introducing the USB-5203
The USB-5203 provides eight differential input channels that are software-programmable for different sensor
categories including thermocouple, RTDs, thermistors, and semiconductor sensors.
Eight independent, TTL-compatible digital I/O channels are provided to monitor TTL-level inputs,
communicate with external devices, and to generate alarms. The digital I/O channels are software-
programmable for input or output.
With the USB-5203, you can take measurements from four sensor categories:
Thermocouple – types J, K, R, S, T, N, E, and B
Resistance temperature detectors (RTDs) – 2, 3, or 4-wire
measurements of 100 Ω platinum RTDs
Thermistors – 2, 3, or 4-wire measurements
Semiconductor temperature sensors – LM36 or equivalent
The USB-5203 provides a 24-bit analog-to-digital (A/D) converter for each pair of differential analog input
channels. Each pair of differential inputs constitutes a channel pair.
You can connect a different category of sensor to each channel pair, but you cannot mix categories among the
channels that constitute a channel pair (although it is permissible to mix thermocouple types).
The USB-5203 provides two integrated cold junction compensation (CJC) sensors for thermocouple
measurements, and built-in current excitation sources for resistive sensor measurements.
An open thermocouple detection feature lets you detect a broken thermocouple. An on-board microprocessor
automatically linearizes the measurement data according to the sensor category.
The USB-5203 features eight independent temperature alarms. Each alarm controls an associated digital I/O
channel as an alarm output. The input to each alarm is one of the temperature input channels. The output of each
alarm is software configurable as active high or low. You set up the temperature threshold conditions to activate
each alarm. When an alarm is activated, the associated DIO channel is driven to the output state.
You can log your sensor measurements to a CompactFlash
®
memory card. CompactFlash is a removable non-
volatile storage device. A 512 MB CompactFlash memory card is shipped with the device to store your data.
For more information, refer to
Logging data with the USB-5203
The USB-5203 device is compatible with both USB 1.1 and USB 2.0 ports. The speed of the device may be
limited when using a USB 1.1 port due to the difference in transfer rates on the USB 1.1 versions of the
protocol (low-speed and full-speed).
External power is required for data logging operations
Due to processing limitations, you cannot log data to the memory card when the USB-5203 is connected to your
computer's active USB bus. When operating as a data logger, disconnect the USB cable from the computer, and
connect the external power supply shipped with the device.
The USB-5203 is a standalone plug-and-play device. External power is required for data logging mode only. All
configurable options are software programmable. The USB-5203 is fully software calibrated.
Logging data with the USB-5203
Due to processing limitations, you cannot log data to the memory card when the USB-5203 is connected to an
active USB port. When operating as a data logger, disconnect the USB cable from the computer, and connect
the external power supply shipped with the device.
The USB-5203 has many software-selectable options for setting up data logging.
You can record:
temperature (
°
C) or raw data from selected input channels
timestamp data
CJC sensor readings
