National Instruments VXI-TB-1000 User manual

NI-VXI™ is a trademark of National Instruments Corporation. Product and company names are trademarks or trade names of their respective
companies.
321528A-01˜ © Copyright 1997 National Instruments Corp. All rights reserved. March 1997
VXI-TB-1000 TERMINAL BOARD CARRIER
This guide describes how to connect signals and install the VXI-TB-1000
terminal board carrier with your VXI-DAQ module, including VXI-MIO,
VXI-SC, and VXI-DIO modules.
Introduction
The VXI-TB-1000 is a carrier for VXI-TB Series terminal boards. You
can configure these terminal boards to match any VXI-DAQ module
configuration. The VXI-TB-1000 populated with terminal boards can
easily accommodate thermocouples, RTDs, strain gauges, thermistors,
millivolt sources, volt sources, and current-loop receivers.
What You Need to Get Started
You need the following items to set up and use your VXI-TB-1000
terminal board carrier:
❑ One or more VXI-TB-1000 terminal blocks
❑ One or more VXI-TB Series terminal boards
❑ VXI-TB-1000 Terminal Board Carrier Installation Guide
❑ VXIbus chassis
❑ One or more VXI-DAQ modules and documentation
❑ Phillips-head number 1 and number 2 screwdrivers
❑ 0.09 in. flathead screwdriver
❑ Long-nose pliers
❑ Wire cutter
❑ Wire insulation stripper

2
If you are using high voltage (≥30 Vrms and 42.4 Vpeak or 60 VDC), please
read the following warnings:
Warning: If high voltages (
≥
≥≥
≥ 30 Vrms and 42.4 Vpeak or 60 VDC) are present, YOU
MUST CONNECT THE SAFETY EARTH GROUND TO THE
GROUNDING LUG. This complies with safety agency requirements
from UL 1244 and IEC 1010 and protects against electric shock when
the terminal block is not connected to the VXIbus chassis. To connect
the safety earth ground to the grounding lug, run an earth ground wire
in the cable from the signal source to the terminal block. National
Instruments is NOT liable for any damages or injuries resulting from
inadequate safety earth ground connections.
Equipment described in this guide must be used in an Installation
Category II environment per IEC 664. This category requires local level
supply mains-connected installation. Do not use this equipment to
measure voltages higher than 300 V.
SHOCK HAZARD: Only qualified personnel aware of the dangers
involved should open this unit. Disconnect all power before removing
the cover. If signal wires are connected to the module or terminal block,
dangerous voltages may exist even when the equipment is turned off.
Before you remove any installed terminal block, disconnect the AC
power line or any high voltage sources (
≥
≥≥
≥ 30 Vrms and 42.4 Vpeak or
60 VDC) that may be connected to the terminal block.
When using the terminal block with high common-mode voltages, you
MUST insulate your signal wires to prevent electric shock by using
300 V wire minimum. National Instruments is NOT liable for any
damages or injuries resulting from inadequate signal wire insulation.
The chassis GND terminals on the terminal block are for grounding
high-impedance sources such as floating source (1 mA maximum). Do
NOT use these terminals as safety earth grounds.

3
Installing Your Terminal Board
Perform the following steps to install the terminal board. The numbers in
parentheses refer to items in Figure 1.
1. Loosen the three cover screws (6) with a Phillips-head number 1
screwdriver. These screws stay attached to the cover (5) without
falling out.
2. Remove the cover (5). You now have access for installation.
3. Place the terminal board (7) into the appropriate half of the terminal
board carrier.
4. Install and tighten the four board screws (8), included with the board,
using a Phillips-head number 1 screwdriver.
5. If you are using only one terminal board, you need to install the
safety shield (10) included with the VXI-TB-1000. Place the safety
shield over the screw bosses (15) and tighten the two safety shield
screws (4), included with the shield, to the screw bosses.
Warning: You must install this safety shield to prevent access to high-voltage
signals.
6. Install the user help card (14) into the raised slots of the cover
insulator (13).
You are now ready to make your signal connections.

4
Figure 1 shows the VXI-TB-1000 terminal board carrier parts locator
diagram.
14
2
12
15
11
10
7
9
8
6
5
13
4
3
1
1 Handle Recess Area 5 Cover 9 Screw Terminal 13 Cover Insulator
2 Mounting Screw 6 Cover Screw 10 Safety Shield 14 User Help Card
3 Grounding Lug 7 Terminal Board 11 Strain-Relief Bar Screw 15 Screw Bosses
4 Safety Shield Screw 8 Board Screw 12 Strain Relief Bar
Figure 1. VXI-TB-1000 Parts Locator Diagram

5
Signal Connection
Perform the following steps to connect the signals to the terminal block.
The numbers in parentheses refer to items in Figure 1.
1. To access the screw terminals (9), remove the terminal block
cover (5) by loosening the three cover screws (6) with a Phillips-
head number 1 screwdriver. These screws stay attached to the cover
without falling out.
2. Choose the wire opening (see Figure 2) through which your signal
wires will pass and loosen the appropriate strain-relief bar
screws (11) with a Phillips-head number 2 screwdriver. You can
completely remove the strain-relief bar (12) for easier access.
3. Use a wire cutter and wire insulation stripper to strip the wire ends as
necessary to connect them to screw terminals.
4. Loosen the screws in the screw terminals (9) with a 0.09 in. flathead
screwdriver.
5. Insert the stripped wires into the screw terminals. Tighten the screws
with a 0.09 in. flathead screwdriver.
6. Replace the strain-relief bar, if necessary, and tighten the strain-relief
bar screws.
Note: If the strain-relief bar screws protrude past the bottom of the terminal block,
replace the screws with 6-32 Phillips panhead screws that are shorter than
3/4 in.
7. Replace the terminal block cover and tighten the cover screws.
You can now connect the terminal block to the VXI-DAQ module front
panel connector.

6
Figure 2 shows the screw terminal board inside the uncovered
VXI-TB-1000 terminal board carrier with one terminal board.
2
1
1 Wire Opening 2 Screw Terminal Board
Figure 2. VXI-TB-1000 Screw Terminal Board
Installing Your Terminal Block
Perform the following steps to connect the terminal block to the
VXI-DAQ module front panel connector. The numbers in parentheses
refer to items in Figure 3.
Note: Before attaching the terminal block onto the VXI-DAQ module front panel
connector, make sure the VXI-DAQ module attachment screws (1) are
tightened to the VXIbus chassis.
1. Guide the terminal block onto the VXI-DAQ module front panel
connector (7) by aligning the terminal block handle recess area (3)
to the ejector handles (2) on the VXI-DAQ module.
2. Connect the VXI-DAQ module front panel connector to its mating
connector (6) on the terminal block.
3. Tighten the top and bottom mounting screws (5) on the back of the
terminal block to hold it securely in place.

7
1
3
5
67
4
8
2
1 Attachment Screw 3 Handle Recess Area 5 Mounting Screw 7 Front Panel Connector
2 Ejector Handle 4 VXI-TB-1000 6 Mating Connector 8 VXI-DAQ Module
Figure 3. Installing the Terminal Block on the VXI-DAQ Module