background image

Take the following precautions to minimize noise pickup and maximize measurement
accuracy:

Use differential AI connections to reject common-mode noise.

Use individually shielded, twisted-pair wires to connect AI signals to the device. With
this type of wire, the signal attached to the positive and negative inputs are twisted
together and then covered with a shield. You then connect this shield only at one point to
the signal source ground. This kind of connection is required for signals traveling through
areas with large magnetic fields or high electromagnetic interference.

Route signals to the device carefully. Keep cabling away from noise sources, such as
video monitors and analog signals.

Use the following recommendations for all signal connections to the NI USB-7846R:

Separate NI USB-7846R signal lines from high-current or high-voltage lines. These lines
can induce currents in or voltages on the NI USB-7846R signal lines if they run in
parallel paths at a close distance. To reduce the magnetic coupling between lines, separate
them by a reasonable distance if they run in parallel or run the lines at right angles to each
other.

Do not run signal lines through conduits that also contain power lines.

Protect signal lines from magnetic fields caused by electric motors, welding equipment,
breakers, or transformers by running them through special metal conduits.

Mounting R Series USB Devices

You can use your R Series USB device on a desktop, mount it on a wall, or mount it on a DIN
rail.

Panel or Wall Mounting

Complete the following steps to panel or wall mount your NI USB-7846R. You can purchase
the panel mounting kit at 

ni.com

 with part number 781514-01.

1.

Use three #8-32 flathead screw to attach the backpanel wall mount to the panel or wall.
Tighten the screw with a #2 Phillips screwdrivers to a torque of 1.1 N · m (10 lb · in.).

2.

Place the NI USB-7846R on the backpanel wall mount with the signal wires facing down
and the device bottom sitting on the backpanel wall mount lip.

3.

While holding the NI USB-7846R in place, attach the front bracket to the backpanel wall
mount by tightening the two thumbscrews.

8

  | 

ni.com

  | 

NI USB-7846R User Manual

Summary of Contents for 7846R

Page 1: ...product specifications These requirements and limits are designed to provide reasonable protection against harmful interference when the product is operated in its intended operational electromagneti...

Page 2: ...vervoltage Protection Overvoltage Protection FPGA Temperature 40 MHz OSC AO x8 USB NI ASIC Kintex 7 FPGA NI USB 7846R Flash Memory DIO 5 V Reference DAC AO ADC AI CONNECTOR 0 DIO CONNECTOR 1 MIO Data...

Page 3: ...DIO9 DIO11 DIO13 DIO15 AO7 AO6 AO5 AO4 AO3 AO2 AO1 AO0 AISENSE AI7 AIGND6 AI6 AI5 AIGND4 AI4 AI3 AIGND2 AI2 AI1 AIGND0 AI0 5V DGND DGND DGND DGND DGND DGND DGND DGND DIO8 DIO10 DIO12 DIO14 AOGND7 AOGN...

Page 4: ...ed or differential voltage signals Use the AISENSE pin to connect non referenced single ended signals Connecting Single Ended Voltage Signals To connect referenced single ended voltage signals to the...

Page 5: ...ial signals to the NI USB 7846R you must also connect the signal reference to AI GND Figure 5 Connecting Grounded Differential Signals to the NI USB 7846R PGIA ADC AI NI USB 7846R Connection Accessory...

Page 6: ...ect a load Figure 7 Connecting a Load NI USB 7846R Connection Accessory AOGND LOAD AO DAC Digital I O The NI USB 7846R provides connections for 48 digital input output DIO channels Connector 0 contain...

Page 7: ...t as input low with pull down resistors To set another power on state you can configure the NI USB 7846R to load a VI when the system powers on The VI can then set the DIO lines to any power on state...

Page 8: ...istance To reduce the magnetic coupling between lines separate them by a reasonable distance if they run in parallel or run the lines at right angles to each other Do not run signal lines through cond...

Page 9: ...s Tighten the screws to a torque of 0 4 N m 3 6 lb in 2 Clip the bracket onto the DIN rail as shown Figure 10 DIN Rail Clip Parts Locator Diagram 1 2 3 1 DIN Rail Clip 2 DIN Rail Spring 3 DIN Rail 3 P...

Page 10: ...riptions Symbol LED Description POWER Solid blue when the power is on USB READY Solid blue when the USB is ready ERROR Solid red for error cases 1 USER USER1 Blue user defined 2 USER USER2 Blue user d...

Page 11: ...ents is not liable for damage resulting from such a connection The power rating is 4 75 to 5 1 VDC at 0 5 A Autonomous Mode You can run the NI USB 7846R without a USB connection to a host computer usi...

Page 12: ...the NI USB 7846R to a host computer before powering off the device Refer to the LabVIEW FPGA Module Help for more information about downloading an FPGA VI to the flash memory Worldwide Support and Ser...

Page 13: ...s section of ni com niglobal to access the branch office websites which provide up to date contact information support phone numbers email addresses and current events NI USB 7846R User Manual Nationa...

Page 14: ...p Patents in your software the patents txt file on your media or the National Instruments Patent Notice at ni com patents You can find information about end user license agreements EULAs and third par...

Reviews: