Data Acquistion

[Roosevelt]

Hi,

I'm having software issues with my MCC-DRV digital output on the USB 1616HS-4. My goal is to control the digital out channels on the DO port 2 portion of the USB 1616HS-4 because I want to activate/deactivate an 8-relay module that I have wired to the USB 1616HS-4 Dig-Ctr I/O. 

A scan rate error pops up when I attempt to run the test and no matter what I change in output module's time base settings, and it continues to pop up. Any suggestions? 

Also, In DASYLab's 2020 and USB 1616HS-4 manuals there's a lack of information on how to handle MCC-DRV's output module. All I can find is the pinout. Is there any configuration I need to do from a software standpoint in order to get those ports and channels functional. 

 

[DAQman]

Hello,

Understand thoroughly the frustration you feel. The fix is to set both the Switch module and the Digital Output module to use the DASYLab time base. By default, the Switch uses the DASYLab time base, and the Digital Output uses the USB-1616HS time base. Below is a picture showing where to set the digital output to use the DASYLab time base. I tested it with the DASYLab time base set to a 10 Hz block size of 1 and found it to work.

Your next problem will be with the 3.3v outputs. I recommend not using them to source current to the relay control. Instead, use an external power source and treat the outputs like an open collector transistor configuration. For example, tie the (+) relay control to your (+) power source and the (-) relay control to the digital output. Then, connect the power source (-) to the USB-1616HS ground. In this configuration, the relay will turn on when the output is set low because the current will flow through the output to the ground like a switch. I hope this help, John

[Roosevelt]

What action would I take to prevent this error message from popping up? 

Thanks for your technical support. All answers you've provided have been clear and helpful. 

[DAQman]

I configured a worksheet with an analog input using channels 0,1,3,8,9 & 10, and I'm not getting the error. Could you attach your worksheet? I will run it with my USB-1616HS-4.

[Roosevelt]

Hi John, 

Is there a way I can click one switch to turn on the I/O ports on my USB 1616HS-4 and have it read the sensors I have wired to the ports, but also have another switch that I can click to start and stop recording my data to an excel sheet. By default, everything is coded to one switch which is no good for the tests I'm trying to execute. 

 

To reiterate, I want to be able to start and stop writing data on command but when I'm not writing data to an excel, I still want to see live data on my digital meter. 

 

[DAQman]

A basic concept with DASYLab is that data is flowing all the time and Relays are used to gate data to different parts depending on the design. So use Relay modules before your Write Data modules. You can tie all the control inputs to a single switch to enable or disable when data is saved.

John

[Roosevelt]

Could you explain more? I'm not as technical as most when it comes to data acquisition. 

From what I see within DASYLab the start/stop module is an output module, so I'll have a difficult time trying to incorporate it. 

I'm just trying to have the "start and stop" operation completely independent from the "start/stop" of recording my data. 

[DAQman]

Attach FinalCopy.dsb and I'll show you what I mean.

John

[Roosevelt]

The attachment is below. 

 

FinalCopy.DSB

Edited March 21, 2023 by Roosevelt

[DAQman]

This is what I had in mind. I couldn't test it because I don't have a PDQ30 expansion module.

FinalCopy2.DSB

[Roosevelt]

Cool, I'm about to test it now. 

What is the switch type for module Switch02? 

[DAQman]

Button with labels turned off

[Roosevelt]

There is a time information or block length error for relay 02. The error causes the run to stop almost immediately.

 

[DAQman]

It's a time base issue. Double-click Switch02; click the Options button on the window that pops up. On the bottom of this window, change the Time base settings to USB-1616HS Device 1 HW. Press okay.

John

[Roosevelt]

Awesome, it works! 

 

Thanks again! 

[Roosevelt]

Hey John, 

Where would I go to change the sample rate from 390Hz to 100Hz? 

 

[DAQman]

The Measurement button on the Analog Input module. Then press Modify. 

[Roosevelt]

 

Hi John, 

 

I'm attempting to add another channel to my digital meter and when I click on the channel, this error message pops up. 

 

Is the max for a digital meter 3 inputs? 

 

[DAQman]

You're not going to like my answer. See how the Analog Input is against the left side of the worksheet and other modules crowd it. The error message  should say, "There is no room to expand the Analog Input module."  The solution is to move the other modules to the right to make room. This may require you to delete and redraw wires. To delete a wire, double-click the right mouse button. Or you could start over with a new worksheet.

[Roosevelt]

Hi John, 

I hope you're having a good day. 

I'm having a small display issue with my software. All of my display modules are chart recorders and I've noticed when I record live the display is not plotting all of the inputs I have going into the module, but the module picks up each input because it has each of them labeled in the legend. Could this be because a chart recorder isn't the most suitable thing for what I'm trying to achieve? should I use a Y/T chart? 

regards, 

[DAQman]

In the lower-left corner, the channel labels are displayed. However, they are not just labels, they also enable and disable the channel. For example, on the PSI Graph, click the label Recorder 0, and it will pop out instead of indented, indicating disabled. Also, you have the plot control showing a single plot. For example, if the temperatures are all very close, it will look like a single trace. On the Chart Recorder, click the Multiple Windows icon found on the ribbon bar to show four mini charts in this case.

[Roosevelt]

Awesome, thanks for that.

On the PSI Graph why is the red indicator thicker than the blue indicator? Is there a way to make it thinner? 

[DAQman]

Fat traces indicate that the signal is rapidly swinging up and down. On the Chart Recorder setup panel, click the x-axis button and set the zoom feature to see better what is going on.