How to choose suitable digital I/O card?

[labviewer]

I have problem in choose suitable digital I/O card to control the instrument switch.
The instrument requirement:
1. NI-card can source 7mA(better 10mA)at each output
pins.
2. The instrument switch is controlled by TTL
level(0-5V).
3. Eight output lines(8pins)is needed for controlling
the switch.

The PCI-650x series produce too small current(2.5mA) so is not suitable.

Should I choose PCI-6527 or DAQcard-6533 or AT-DIO-32HS? I am somewhat confused above three card capacity.My hope is the card is cheap and can realize above request.

Thank you !
zhou

[Filipe A.]

Hello;

The choice will depend on what sort of application you need. If you can do Software timing operations (each time that you need to update the digital port you will need to make a function call) you can use the 6527. If you need accuracy pattern generation you will need the 32HS board. The 6527 is cheapper but by doing Software timing operations you won't have much accuracy on the update time (because your Software will run under Windows). So, your choice will rely on how you need to communicate with your external device.
Hope this helps.
Filipe