Measurement Computing Personal Daq rev.6.0 - Manual (Page 21)

Personal Daq User’s Manual 878695 General Information & Specifications 2-1
General Information & Specifications 2
General Description ……2-1
Channel Capacities ……2-1
Features ……2-2
Theory of Operation ……2-3
Universal Serial Bus (USB) ……2-3
Power Line Rejection ……2-3
Optical Isolation …… 2-4
A/D Conversion ……2-4
Input Ranges ……2-4
Analog Input Configuration ……2-5
Measurement Duration, Sample Rate, and
Resolution ……2-5
Automatic Calibration …… 2-7
Thermocouple Measurements ……2-7
Frequency Measurements ……2-8
Digital I/O ……2-8
Personal Daq Specifications ……2-9
Analog Specifications ……2-10
Input Voltage Ranges ……2-10
Voltage Specifications ……2-10
Temperature Specifications …2-11
Thermocouple Accuracy ……2-11
Frequency Specifications ……2-12
Digital I/O Specifications……2-12
General Specifications ……2-12
Optional Accessories …… 2-12
Channel Connection Layouts ……2-13
Calibration ……2-15
General Description
Personal Daqs are compact data acquisition devices that make use of the Universal Serial Bus (USB).
They can be located up to 5 meters (16.4 feet) from the host PC, allowing the unit to reside close to the
point of measurement. This reduces noise and improves reading accuracy. USB provides both high-speed
communication and power to the Personal Daq, allowing for a single cable connection to the PC. No
additional power supplies are required, except in special setups of multiple units, or when connected to
certain notebook PCs.
Note: Advanced setups, using several Personal Daq units, are possible. These setups require USB hubs
(self-powered or USB-powered). In addition, depending on the setup, certain Personal Daqs in the
system may require connection to a power adapter as indicated in Chapter 3, Hardware Setup.
Note: Certain notebook PCs require the use of a power adapter with the Personal Daq. Chapter 3
contains more information regarding power adapters.
Personal Daq/55 and /56 allow for system expansion by snapping a PDQ expansion module onto the unit.
Chapter 3, Hardware Setup, contains detailed information regarding various setup options.
Although Personal Daq/54 has a 25-pin connector, it does not accept expansion modules . The
connector, in the case of Personal Daq/54, is used only for calibration as discussed in chapter 6.
Channel Capacities
The following table highlights the differences between modules and provides a means for calculating the
total channel capacity of a Personal Daq system.
Channel Capacities for Various Personal Daq Setups
Personal Daq/54 Volts Inputs TC Inputs Digital I/O Freq/Pulse Inputs
Personal Daq/54
----
No Expansion ----
5 DE, or 10 SE 5 DE ---- N/A ---- ---- N/A ----
Personal Daq/55 Systems Volts Inputs TC Inputs Digital I/O Freq/Pulse Inputs
Personal Daq/55 5 DE, or 10 SE 5 DE 8 2
Personal Daq/55 with PDQ1 15 DE, or 30 SE 15 DE 24 2
Personal Daq/55 with PDQ2 25 DE, or 50 SE 25 DE 8 2
Personal Daq/56 Systems Volts Inputs TC Inputs Digital I/O Freq/Pulse Inputs
Personal Daq/56 10 DE, or 20 SE 10 DE 16 4
Personal Daq/56 with PDQ1 20 DE, or 40 SE 20 DE 32 4
Personal Daq/56 with PDQ2 30 DE, or 60 SE 30 DE 16 4
DE = Differential Mode, SE = Single-Ended Mode