NATIONAL INSTRUMENTS NI TB-2708 (01) PDF Document

The NATIONAL INSTRUMENTS NI TB-2708 is a terminal block assembly designed for use with PXI-6115/6120 S Series devices. It consists of nine SMB connectors for analog signals and a 14-pin I/O connector for digital signals. The terminal block connects directly to the front panel of National Instruments PXI-6115 and PXI-6120 devices, which eliminates the need for an external cable.

The main components of the NATIONAL INSTRUMENTS NI TB-2708 are:

1. Access Door to Configuration Switches

2. 14-Pin I/O Connector (for Digital Signals)

3. SMB Connectors (for Analog Signals)

To set up and use your NATIONAL INSTRUMENTS NI TB-2708 terminal block, you will need the following:

– NI TB-2708 Terminal Block Assembly

– NI TB-2708 Installation Guide

– One of the following S Series devices: NI PXI-6115 or NI PXI-6120

– S Series User Manual

– Number 1 Phillips screwdriver

Please adhere to the following safety precautions when using the NATIONAL INSTRUMENTS NI TB-2708:

ESD Warning: The connectors are sensitive to electrostatic discharge (ESD). You should ground yourself prior to connecting or disconnecting signals.

Voltage Limit: Do not apply an input voltage greater than 42 Vpk/60 VDC. Input voltages greater than this can damage the TB-2708, any connected device, and the host computer. Overvoltage can also cause an electric shock hazard.

Operating Environment: Do not operate the device in an explosive atmosphere or where there may be flammable gases or fumes.

Damaged Equipment: Do not operate damaged equipment. If the device is damaged, turn it off and do not use it until service-trained personnel can check its safety.

Modifications: Do not substitute parts or modify the equipment. Do not install unauthorized parts.

Signal Connections: You must insulate all signal connections to the highest voltage with which the TB-2708 can come in contact. Connections that exceed the maximum signal ratings can create a shock or fire hazard.

Cleaning: Clean the module and accessories by brushing off light dust with a soft non-metallic brush. The unit must be completely dry and free from contaminants before returning it to service.

To connect the NATIONAL INSTRUMENTS NI TB-2708 terminal block to the PXI module I/O connector, complete the following steps:

1. Install the PXI module into the chassis and tighten the two module screws. You must install the PXI device before connecting the TB-2708.

2. Guide the terminal block onto the PXI module connector. Caution: Do not force the terminal block when inserting it into or removing it from the PXI module I/O connector.

3. Tighten the two terminal block mounting screws.

The following table provides a brief description of each signal available on the NATIONAL INSTRUMENTS NI TB-2708.

You can use the NATIONAL INSTRUMENTS NI TB-2708 to measure both floating and ground-referenced analog input signals by adjusting a switch for each AI channel.

Measuring Floating Signals:

To measure floating signal sources, move the switch located under the rubber-sealed door on the enclosure cover for the AI channel to the ON (floating source) position. In this position, the amplifier negative terminal connects to ground through a 5 kΩ resistor in parallel with a 0.1 µF capacitor. This is the recommended configuration for floating sources.

Measuring Ground-Referenced Signals:

To measure ground-referenced signals, it is possible to use either the floating (ON) or ground-referenced (OFF) switch position. However, for best results, use the OFF (ground-referenced source) switch position to avoid ground loops. This is the recommended configuration for ground-referenced sources.

The following table summarizes the proper configurations:

A 14-pin connector on the bottom of the NATIONAL INSTRUMENTS NI TB-2708 provides access to digital I/O signals. To access these signals, use the MFIT-Pigtail Cable Assembly (part number 194123-01). This cable has a 14-pin I/O connector on one end and pigtail conductors on the other end for termination. The pin assignments and wiring information are listed below:

The following National Instruments cables are available for connecting the NATIONAL INSTRUMENTS NI TB-2708 to analog and digital user signals:

Physical Specifications:

Dimensions: 10.7 x 8.6 × 2.0 cm (4.2 x 3.4 x 0.8 in.)

Weight: 144.6 g (5.1 oz)

I/O connectors:

– 68-position SCSI-II type: 1, female

– SMB jacks: 9

– 14-pin auxiliary connector: 1, Molex 14-pin microfit connector

Environmental Specifications:

The NATIONAL INSTRUMENTS NI TB-2708 is intended for indoor use only.

Operating temperature: 0 to 55 °C

Storage temperature: -20 to 70 °C

Relative humidity: 10 to 90% noncondensing

Pollution Degree: 2

Operational shock: 30 g peak, half-sine, 11 ms pulse (Tested in accordance with IEC-60068-2-27. Test profile developed in accordance with MIL-PRF-28800F.)

Random vibration:

– Operating: 5 to 500 Hz, 0.3 grms

– Nonoperating: 5 to 500 Hz, 2.4 grms (Tested in accordance with IEC-60068-2-64. Nonoperating test profile exceeds the requirements of MIL-PRF-28800F, Class 3.)

The NATIONAL INSTRUMENTS NI TB-2708 is designed to meet the requirements of the following standards of safety for electrical equipment for measurement, control, and laboratory use:

– IEC 61010-1, EN 61010-1

– UL 61010-1, CSA 61010-1