09-18-2002 09:48 AM
09-18-2002 05:45 PM - last edited on 01-03-2024 10:45 AM by migration-bot
Are you talking about the PCI-6025E? The various ports on the 6025E are controlled by different chips and do indeed have different current sourcing capability. The DIO 0-7 lines are controlled by the DAQ-STC chip and can source about 13mA and can sink even more. The PA, PB, and PC lines are controlled by a separate 82C55A chip which can only source or sink 2.5mA. Please see pages 3-1 and A-7 in the 6025E User Manual for more information.
If you need higher current capability on more than 8 lines, you could use the ER-8/16 relay modules. Please see Figure 3-3 on page 3-9 of the
ER-8/16 User Manual for details on connecting the relay modules to your DAQ board. This manual was published before the 6025E released, however the compatibility is the same as the AT-MIO-16DE-10. Configurations A, B, and C are valid for your board and will give you an additional 8, 16, or 24 lines respectively.
Regards,
Brent R.
Applications Engineer
National Instruments
09-19-2002 09:39 AM
09-19-2002 10:16 AM - last edited on 01-03-2024 10:47 AM by migration-bot
Well, first it is important to find out how much current the relays will take. The lines on the DIO port of the 6025E can source/sink up to 24 mA. So if you can find the impedance of your relays, you should be able to calculate whether or not you are exceeding the current limitations of your DIO.
Now, perhaps a better device for your application would be the 6527 Isolated DIO board. The solid-state relays on this board can handle up to 250 mA! Otherwise, you will need an external module such as the ER-8/16 or the SC-2061. In either case, you will have to look at the User Manuals to make sure they can handle the amount of current you require.
Hope this helps!
Russell
Applications Engineer
National Instruments
http://www.ni.com/support
09-19-2002 10:49 AM - last edited on 01-03-2024 10:48 AM by migration-bot
How much is "adequate" current output? If the DIO lines on the 6025E were working fine, then adequate seems to be 10mA or so. The 6527 would be perfect for up to 24 channels. It will switch 120 mA, which sounds like it should be plenty. The 6533 is overkill in terms of speed (20 MHz), but it'll provide 24mA and would be good for up to 32 channels.
If you can make do with 24 channels, the 6527 is ideal. It's very inexpensive and it works with the 100 pin cable you probably already have.
Regards,
Brent
09-19-2002 11:12 AM
09-24-2002 08:23 AM
09-24-2002 09:47 AM - last edited on 01-03-2024 10:49 AM by migration-bot
Yes, the 6527 should be ideal for your application. You'll also need an external 12V power supply in order to provide the drive current for the valves. This is pretty much unavoidable, afterall a computer's power supply can only do so much. (The outputs on the 6527 are actually solid-state relays.) The 6527 User Manual should tell you every thing you need to make your connections properly.
Best Regards,
Russell
Applications Engineer
National Instruments
http://www.ni.com/support
09-24-2002 10:22 AM
09-24-2002 11:17 AM