National Instruments NI USB-6525 User Manual

USER GUIDE AND SPECIFICATIONS

NI USB-6525

This user guide describes how to use the National Instruments USB-6525
data acquisition (DAQ) device.

Introduction

The NI USB-6525 is a full-speed USB 2.0 device that provides
eight ±60 VDC channel-to-channel isolated digital inputs (DI),
eight 60 VDC/30 Vrms channel-to-channel isolated solid-state relay (SSR)
outputs, and a 32-bit counter.

1

1 USB Cable Strain Relief

Figure 1. USB-6525 Top View

Installing Software

Software support for the USB-6525 for Windows 2000/XP is provided by
NI-DAQmx.

The NI-DAQmx CD contains example programs that you can use to get
started programming with the USB-6525. Refer to the NI-DAQmx for USB
Devices Getting Started Guide, that shipped with your device and is also
accessible from Start»All Programs»National Instruments»NI-DAQ
for more information.

Note For information about non-Windows operating system support, refer to ni.com/

info

and enter rddqld.

Hardware

The block diagram in Figure 3 shows key functional components of the
USB-6525.

Figure 2. USB-6525 Back View

Vbus

USB Microcontroller

USB

Full-Speed USB Interface

USB-6525 User Guide and Specifications 2 ni.com

P0

P1

Figure 3. USB-6525 Block Diagram

SSRs

Current-

Limiting

Isolated

Inputs

P0.<0..7>A/B

P1.<0..7>+/–

Digital I/O Terminal Block

Refer to the Safety Guidelines section of this document for important safety
information.

Setting Up Hardware

Complete the following steps to set up the hardware:

1. Install combicon screw terminal blocks by inserting them into the
combicon jacks.

Note The USB-6525 kit ships with signal labels. You can apply the signal labels on the

screw terminal blocks for easy signal identification.

2. Refer to Table 1 and Figure 4 for label orientation and affix provided
signal labels to the screw terminal blocks. Insert the screw terminal
blocks into their respective matching combicon jacks. Refer to
Figure 4 for more information about signal label orientation.

1

2

3

4

1 Overlay Label with Pin Orientation Guides
2 Combicon Jack

3. Connect the wiring to the appropriate screw terminals.

3

3 Screw Terminal Blocks
4 Signal Labels

Figure 4. Signal Label Application Diagram

4

© National Instruments Corporation 3 USB-6525 User Guide and Specifications

I/O Connector

The USB-6525 device ships with two detachable terminal blocks for digital
signals. Each individual terminal accepts a wire gauge between
16 AWG–28 AWG.

Table 1. Digital Terminal Assignments

Module Terminal Signal Module Terminal Signal

1 P0.0A 17 P1.0+

2 P0.0B 18 P1.0–

3 P0.1A 19 P1.1+

4 P0.1B 20 P1.1–

5 P0.2A 21 P1.2+

6 P0.2B 22 P1.2–

7 P0.3A 23 P1.3+

8 P0.3B 24 P1.3–

9 P0.4A 25 P1.4+

10 P0.4B 26 P1.4–

11 P0.5A 27 P1.5+

12 P0.5B 28 P1.5–

13 P0.6A 29 P1.6+

14 P0.6B 30 P1.6–

15 P0.7A 31 P1.7+/PFI 0+

16 P0.7B 32 P1.7–/PFI 0–

USB-6525 User Guide and Specifications 4 ni.com

Signal Descriptions

Table 2 describes the signals available on the I/O connectors.

Table 2. Signal Descriptions

Signal Name Direction Description

P0.<0..7>A/B Output Solid-state relay 60 VDC/30 Vrms (42.4 Vpk) output

P1.<0..6>+/– Input ±60 VDC digital input.

P1.<0..6>+ corresponds to the positive input terminal.

P1.<0..6>– corresponds to the negative input terminal.

P1.7+/– or PFI 0+/– Input This channel is configurable as either a digital input or

an event counter.

Digital Input Signal—±60 VDC digital input.

P1.7+ corresponds to the positive input terminal.

P1.7– corresponds to the negative input terminal.

CTR—As a counter, this signal can be used as an event
counter input source.

PFI 0+ corresponds to the positive counter terminal.

PFI 0– corresponds to the negative counter terminal.

Digital I/O

USB-6525 has eight channel-to-channel optically isolated inputs,
P1.<0..7>, and eight channel-to-channel optically isolated solid-state relay
outputs, P0.<0..7>. P1.7/PFI 0 can also function as a 32-bit counter. Refer
to the Event Counter section for more information about the counter.

Optically Isolated Inputs

The USB-6525 provides eight channels of isolated digital inputs. These
inputs consist of an optocoupler, a depletion-mode MOSFET-based
current-limiting circuit, and Schottky diode.

Each channel has its own positive and negative terminals. The input range
on the channels is –60 VDC to +60 VDC.

Sensing DC Voltages

The USB-6525 detects a wide range of DC signals, from TTL-like logic
levels to DC power supply levels up to 60 V.

© National Instruments Corporation 5 USB-6525 User Guide and Specifications