PCI 6503

[birdbrain]

Hi I am using a custom software configured to send a 5 volt output through the PCI 6503. At the output I read the 5 volt , but when I connect a device (eg. a bulb, a motor or a solenoid) that should be activated by 5 volts, it doesn't. I am completely new to this and don't know much. Any help will be greatly appreciated. 

[MXI Master]

birdbrain,

How much current does your device need?

The PCI-6503 sources or sinks a maximum of 2.5mA per channel, this is possibly not enough to satisfy the draw of your device causing the signal to distort. It is best to connect the 6503 to a relay or amplifier if you need more power. If you are within this spec please post back and we can discuss it further.

[birdbrain]

Thanks maxi master. Like I said, I am completely new to this. Can you suggest a relay or an amplifier.

[samantham]

Hello,

I understand that you are new to this.  You are using a Digital Input/Output device 6503 that is intended as a logic device and not intended as a current driver for LEDs, SSRs, mechanical relays … ect.  This device only provides a typical current of 2.5 mA and a maximum of 4 mA.  The voltage level provided depends on the amount of current being sourced from the device.  Attempting to source more than this can cause damage to the device 82C55 PPI. 

“If you require higher current drive, consider using the NI PCI/PXI-6509 5V/TTL 96-line Industrial DIO board with 24 mA current driver, using an NI PCI/PXI-651x high-current drive Industrial DIO board, or using external circuitry such as Darlington Arrays to increase the current drive of digital output lines.” 

This is from the manual of your device on page A-2.  I have also attached below a helpful KnowledgeBase that explains the output logic levels.

AE KB 2OKIKCH5: Why Are There Two Different Output Logic High and Low Levels for the PCI-DIO-96?

National Instruments unfortunately does not sell any Darlington Arrays.  Please let me know what level of current you are interested in supplying to a device.