Right Y-axis Hash on Stripchart

[hendra@ngms]

I am running a continuous stripchart. Moved from Left Y-axis to right.  There is hash on the zero line, comes and goes.  See the attached images. 

Is this a bug in the Stripchart control, or am I setting it up incorrectly.  The exaxt same settings worked perfectly when I was using Left Y-axis.

CVI 2013SP1, WinXP and Win7

[LindsW]

Hi,

When you say that you moved from left y-axis to right, do you mean that you changed the y-axis labels from displaying on the left side of the graph to the right?  If so, which properties exactly did you change?

Also, when you run the same code repeatedly are the hash marks appearing in the same manner, or are they appearing erratically? Finally, would it be possible for you to share your code, or a portion of your code with us so that we can try replicating the issue?

Regards,

[hendra@ngms]

Having seen no replies for a couple days, I was just about to ask for technical assistance when I saw your reply.  Should I go ahead and open a ticket, or converse with you?  Directly?  I could send you screenshots much easier via e-mail.

My problems with strip chart controls are:

1.  The Right hand Y-axis hash, which seems to be associated with tick marks placed on the 0 line.  More on that later.

2.  How can one contol the grid, so that minor divisions make sense.  I do these strip charts to have major divisions one minute in duration.  The control seems to figure out it's own number of minir grid lines -- often 8, sometimes 9, rarely 6 or 10, which would make sense.  I ran across this: "XMinorGridVisible:  Specifies whether to show or hide the minor grid lines for the x-axis on the graph. In order for the minor grid lines to be visible, you must also set the Show Grid option.
The number of minor grid lines that are visible when this option is enabled is proportional to the space between consecutive major grid lines. In some cases, when this space is too small, it's possible for this number to be zero."   How about a selection for number of grid lines, or maximum number of grid lines (I would select 6, so that it represented 10 seconds per minot grid line).

In answer to your questions:

1.  Since the continuous data appears on the right side, having a left-side Y-axis is very difficult.  I disabled the left-axis, connected the two traces to the right-hand Y-axis, and otherwise set the control up the same way.  I can provide more screenshots.  (Why can't I set up left and righ Y-axes to appear exactly the same?  IE, traces connected to both).  I use autoscaling almost exclusively with these strip charts.

2.  The hash marks shown in the screenshots I sent are erratic.  They appear at the far right edge, and grow like worms, eventually connecting together.  If I switch from Autoscale, to fixed scale and back, they disappear, and start to grow again.  BTW, the hash appears to be associated with the tick marks.  The X-axis appears to insert 5 tick marks per minute, completely independent of the grid, which may at the same time show 8 minor divisions per minute.  These X-axis 5 tick marks appear only when operating the Y-axi in autoscale, not fixed scale.  So the hash is associated with the 5 tick marks, only in Autoscale, and is a screen-drawing artifact, because they are erased completely when changing from auto to fixed and back to auto.  If the strip chart control is on a tab control, when a different tab is in the foreground, the worms do not grow, until the tab with the strip chart control is back in the foreground.

3.  Yes, I can provide code.

Doesn't seem to matter what the write rate is.  One Strip Chart control is updated 4 times each second, the other 10 times each second.

Regards... Gary

[LindsW]

Hi Gary,

Thanks for the additional information.  You are more than welcome to create a service request.  If you decide to do so, be sure to reference this post so that I can collaborate with the Applications Engineer who receives your service request.  However, I believe I have the answer you are looking for:

I have been looking into this issue, and have been able to re-create it on my end.  From what I can tell, it seems to occur when the “Show Grid” option is enabled on the “Edit Axis Settings” Dialog for the Right Y-Axis, while using “Auto Divisions.”

This was reported to R&D (CAR #461922) for further investigation.  A possible workaround is to disable the “Auto Divisions” option in the “Edit Axis Settings” Dialog for the Right Y-Axis, and then setting the “Divisions” field to a specific number.

I believe the ability to change the number of Divisions also answers your question on how to specify the spacing of the gridlines, but let me know if you have more questions!  And thanks for your feedback!

Regards,

[hendra@ngms]

Lindsey,

I'm not sure what you recreated, because your suggestion does not address either of the two probelms I presented in the last post.  I do not have any problem with Y-axis scaling, divisions or sub-divisions.  Only X-axis.

I did as you suggest, and the attached figure is the reult.  Note the garbage on the Y-axis labels.  Hash is still there.  And there are 9 subdivisions during each minute.

Gary

[LindsW]

Hi Gary,

Perhaps I have misunderstood the issue.  I have attached a screenshot, "BugScreenshot.png," with a red box around what I believed we were trying to troubleshoot.

Additionally, I have attached some screenshots of how I removed these tick marks.  It is my understanding that these tick marks should not be included when adding y-axis grid lines.

If you are talking about something else, would you mind attaching a screenshot of the settings dialog with the options you are using?

Regards,

[hendra@ngms]

Chris:

Demo Project.

[JonathanN]

Gary,

Does the workaround provided address your issue?

[hendra@ngms]

No.  I worked through support on this.  They found it is a bug, and I believe they have submitted this for a future fix.

[LuisG]

Bug id: 461922