Supported Triggers in PCI 6602 for Counter input / counter output operations

[johnsonpm]

Hi,

Could you please provide me the supported Triggers for the PCI device 6602.

I am using counter input channel as well as counter output channel for a particular application.

I am using NI DAQmx 8.5.

My understanding is that

1. Counter Output channel supports Pause,Start and ArmStart triggers and

2. Counter Input channel uses only two triggers Pause and ArmStart trigger. Does this understanding correct?

For a pulse generating counter, If I use Start Trigger how do I configure the channel?

Can I use both the Start trigger and Arm Start Trigger for this pulse generating counter ?

Johnson

[Bueller]

Hi Johnson,

Thank you for posting on the discussion forums.

There are very nice examples in LabVIEW that do what you are looking for. You can find those examples in LabVIEW

under Help >> Find Examples >> Hardware Input and Output >> DAQmx >> Generating Digital Pulses.

The examples will also confirm what kind of triggers you can use. The first example in particular uses a start trigger.

Regards,

Faris A

[johnsonpm]

Hi Faris,

Thank you for your reply.

The examples mentioned in your reply are not useful to me as I am using C/C++ Programming Language and I am very unfamiliar with LabVIEW.

My question is whether am I able to use the same StartTrigger signal for both Counter input channel and another counter output channel in a PCI 6602 Device for a synchronous operation.

I have mentioned the understandings on the first post based on my experiments with simulated device. But somewhere in the documentation,I read that simulated devices have some limitations regarding triggering clock etc. So I just need to confirm it is same in actual hardware as I am not provided with the hardware.

I want to trigger start both the counter input channel and counter output channel from a single external line.

What would be best trigger (like arm start, start, pause) suited for this application? 

Thanks for your help

[Bueller]

Hi Johnson,

You can use the same start trigger to trigger both counters.

Check this Link to know where you can locate some useful visual C++ examples.

Faris A

[johnsonpm]

Hi Faris,

In fact when I used DAQmxCfgDigEdgeStartTrig() function to configure the start trigger for a task with buffered event counting channel, It caused an error like the specified property is not supported in the task or the device.

But I could set the startTrigger for the continuous pulse generation channel using the function DAQmxCfgDigEdgeStartTrig() without any errors

( I am using simulated devices for development).

Is that because the buffered event counting channel does not support a StartTrigger, but only supports pause trigger and arm start trigger?

Let me check again whether I am able to use the same start trigger for both the channels (without ArmStartTrigger).

If I configure the Arm Start Trigger for a counter task, when will the counter starts counting?  If  I call the StartTask function after configuring the StartArmTrigger terminal, I assume that the counter starts counting at the moment a trigger pulse occurs at StartArmTrigger terminal? Is this correct?

Thanks in advance,

Johnson

[Bueller]

Johnson,

The counter starts  counting at the moment a trigger puls occurs at StartArmTrigger terminal.

In general, if there's no error in the software, and you are getting  " specified property is not supported in the task or the device", then that means that the device does not support such an operation.

let me know how it goes

Regards,

Faris A

[johnsonpm · Accepted solution]

 I am sorry, it took a long time to test my application in an actual NI PCI 6602 card. I am now convinced that counter out put channels support start trigger, pause trigger and arm start trigger. But counter input channels use pause trigger and arm start trigger only.

I have designed the application such way that counter 0 is used as a counter input channel and counter 1 is used a counter output channel. Both channels are configured to use arm start triggers. Arm start triggers are expected to come from an RTSI line. Using the connect terminal API to route RTSI line 0 to arm start trigger of both channels. So when a pulse comes at RTSI line 0 both counter starts counting.

One more thing I would like to know is that how RTSI signals are generated? I know RTSI is used for syncing multiple NI boards.

If there is only board can we use  the RTSI signal?

Can the PCI 6602 hardware itself generate any signals at RTSI lines?

Thanks in advance.

Johnson