Don't forget the free-wheeling diodes

[skatta3]

Hi,

1. I need to select  a right module for exciting solenoid valve which requires 24DC  V.  As per the forums, The maximum voltage that can be provided is 10V from NI 9237.  

2. Also I need to operate 8 solenoid valves simultaneously. Can anybody suggest ?

[K C]

Look at this link. There are also 24V devices for sourcing and sinking.

The voltage off 24V is not the problem. The power you need could be a problem.

Kees

[Buechsenschuetz]

Yes, the power might be a problem. It would be helpful to provide us with the data of your solenoid valve. 

Also, some solenoid valves need a high "inrush" current to move the solenoid quickly and a lower current level for holding the solenoid valve open. We are using a module which can be set to a high current for a certain period and after that will deliver a lower current level. The input can be driven with a 5V signal (approx. 10mA), most I/O boards can handle these values in sink mode. 

http://www.geeplus.biz/FTPROOT/control%20circuits.pdf

[johnsold]

If the solenoid coils are rated for DC and require less than 500 mA, then the ULN2003 driver IC may be all you would need.

Lynn

[skatta3]

http://www.mcmaster.com/#8214k513/=101uza1 - Here is the link for the solenoid valve specification. I am looking for I/O modules that are suitable for NI DAQs

[skatta3]

0.48 A is the maximum current required for energising the valves

[Agamemone]

I assume you mean "minimum", but I just wanted to be sure. Could you clarify?

[skatta3]

It is the maximum current drawn by the valve as per the specification.

[Agamemone]

The 9472 has 8 Digital Output Channels that can source .75 A at between 6 and 30 V. It sounds like it would meet your specifications. I am including a link below:

https://www.ni.com/en-us/shop/model/ni-9472.html

[SteveD123]

A few points:

1. Remember to put free-wheeling diodes across the coil of each solenoid. See https://en.wikipedia.org/wiki/Flyback_diode This will eliminate spikes when you remove power from each solenoid.

2. Our normal practice would be to use solid state interface relays between the NI output card and each solenoid, e.g. http://uk.rs-online.com/web/p/solid-state-relays/7761434/ This allows you to completely isolate the solenoids from the PC circuits. This means that solenoid interference into your I/O, including any sensitive analogue I/O is greatly reduced, and faults and physical failures in your plant-side wiring (e.g. accidental connection to 415 volts) will not damage your instrumentation & PC.

3. Using separate interface relays and a separate power supply for the solenoids solves your final issue of operating all 8 solenoids at the same time: The separate power supply just has to have enough grunt to cope with the inrush current of all 8 solenoids at the same time.