Measurement-computing Personal Daq rev.6.0 Instrukcja Użytkownika Pobierz pdf (Strona 22)

2-2 General Information & Specifications

878595 Personal Daq User’s Manual

Note: With the use of USB hubs up to 100 Personal Daq units can be attached to one PC. With 100

Personal Daq/56 modules (each with a PDQ2 expansion module) a total channel capability of

8,000 channels can be obtained. An example of capacity calculation follows.

Calculating System Channel Capacity, An Example

Assume a Personal Daq system is comprised of the following:

• one Personal Daq/56 unit

• one PDQ2 expansion module

Using the table on page 2-1 (looking in the bottom row) we see that a Personal Daq/56 with PDQ2 can accept the

following types of channel connections:

• 60 single-ended (or 30 differential mode) for volts inputs

• 30 differential mode for thermocouple inputs

• 16 Digital I/O

• 4 Frequency/Pulse inputs

The maximum channel capacity in this set up is 80 channels. With the use of differential mode

(instead of single-ended) the maximum channel capacity is 50 channels.

In Personal Daq applications, thermocouples should not be connected single-ended. Doing

so can result in noise and false readings. This is especially true when acquiring other high-

amplitude signals in conjunction with thermocouple signals that are connected single-ended.

Features

The Personal Daq system includes the following features:

• USB connection to the PC means no batteries or other power sources required (see notes)

• signal input connections via removable screw-terminals

• high-resolution 22-bit A/D converter

• internal cold-junction compensator for direct thermocouple measurements

• 500 VDC isolation for PC protection

• low noise thermocouple and voltage measurements

• full-scale voltage inputs from –10 VDC to +20 VDC

• frequency/pulse measurements from DC to 1 Mhz (Does not apply to Personal Daq/54)

• digital I/O with current sink capability for direct drive applications

• with addition of PDQ expansion module, up to 80 channels of analog and digital I/O are available

for one Personal Daq/PDQ combined unit (Does not apply to Personal Daq/54)

• up to 100 Personal Daq/PDQ (combined units) can be connected to one PC by the use of USB hubs;

providing a total channel capacity of 8,000 channels

• digital calibration eliminates the need for potentiometers and user adjustments

• Personal DaqView and driver software

• external power input jack for use with notebook PCs and various setups (discussed in Chapter 3)

Note 1: Certain system configurations make use of USB hubs and power adapters, as discussed in

Chapter 3.

Note 2: Some notebook PCs require that a power adapter be used with your Personal Daq.

Chapter 3 contains more information regarding power adapters.

1 2 ... 17 18 19 20 21 22 23 24 25 26 27 ... 169 170

Brak uwag

Measurement-computing Personal Daq rev.6.0 Instrukcja Użytkownika Strona 22