Board with watchdog timer and current output

[Rod42]

Hello,

Hope someone can advise me on a suitable board for my application.

I need to add a watchdog facility to some existing LabVIEW, such that if the watchdog expires it sounds an external buzzer. On looking through the NI literature I see that there are a number of cards with a watchdog facility. However, I would like the card to provide the power for the buzzer, 30mA / 5V should be sufficient,  so all I need to do is connect a buzzer to the card's output. I have been advised by NI of two possible cards (PCI 6514, 6515) but it is not clear to me whether the cards simply have a to simply *switch* current up to the stated limit, or if they can *provide* the current. [The stated current drive exceeds the board's power consumption] Due to the simpler connector, I'd prefer to use the similar, (but not suggested by NI) PCI 6516 if that's possible

I'd be grateful for feedback.

Thanks,

Rod.

[TimM(AE)]

Hi Rod

I have attached a bit more information about some of the cards, the help file for the 65XX devises and a knowledge link for Sinking and sourcing. As you want a card to provide the power you want a sourcing cared i.e. the 6514 or 6516 as you said earlier.

I don’t understand what you mean by this comment

simply *switch* current up to the stated limit, or if they can *provide* the current

The NI 6514/6515 devices are 30 V bank isolated data acquisition (DAQ) devices for PCI, PXI, or CompactPCI chassis. The NI 6514/6515 devices feature 32 digital input lines and 32 digital output lines for sourcing (6514) and sinking (6515) current, a watchdog timer, digital filtering, and programmable power-up states.

The NI 6516/6517 devices are 30 V bank isolated data acquisition (DAQ) devices for PCI chassis. The NI 6516/6517 devices feature 32 unidirectional digital output lines for sourcing (6516) and sinking (6517) current, a watchdog timer, and programmable power-up states.

DI/O help

http://digital.ni.com/manuals.nsf/websearch/C17970161F11D53A86256F19006E693C

Understanding Sinking and Sourcing

http://digital.ni.com/public.nsf/websearch/A10122C63A7F5CFE86256B4C007491DD?OpenDocument

I hope this makes it easier to make an informed decision

Tim

NI UK AE

[Rod42]

Thanks for that Tim, but I still don't understand.

The help file you indicated shows that one should connect an external power supply to VCC on either the 6514 or the 6516 to drive the load. What I need is to connect a load, say between Px and GND, without the need for an external power supply. (The load would be switched on upon expiry of the watchdog) The load I have in mind would require about 30mA at 5V

Rod.

[TimM(AE)]

Hi Rod

I have had a good look and I can’t find a PCI card that will source that much power with a hardware watch dog, i think this is due mainly to PCI specifications. You will have to use an external power supply and either an amplifier or really setup depending on whether or not you need a varying current.

Regards

Tim

[TimM(AE)]

or even a relay setup