Welcome to Synthiam!

The easiest way to program the most powerful robots. Use technologies by leading industry experts. ARC is a free-to-use robot programming software that makes servo automation, computer vision, autonomous navigation, and artificial intelligence easy.

Get Started
USA
Asked — Edited

Intermittent Exception Error When Trying To Start Custom Http Server?

I originally posted this thread in another topic discussion, but thought it should maybe start a different thread for this discussion. Below, is what I posted in a previous discussion on the HTTP Custom Web Server Control:

I noticed that when I activate the custom web server in my project sometimes I get the following exception error:

"Object reference not set to an instance of an object"

It does not happen all the time. It is intermittent. Not sure what is up with this?

I did change the custom EZ-Script button to the following: ControlCommand ("Script 4",ScriptStart). When I depress the button it pans camera right as it should. Just wondering if I should have a ControlCommand ("script 4",ScriptStop) command in the server page or the (Script 4) itself? When I quit the server and enable it again before I do anything with the page, it comes up with this error. Not sure what might be going on here? When this error comes up I have to exit the program from the task manager or it will start deleting controls from my project page. Problem seems to be related to the http custom server. It should be noted I'm not using the script manager control. Any thoughts on this would be much appreciated and thanks again ! Rick
:):)


ARC Pro

Upgrade to ARC Pro

ARC Pro will give you immediate updates and new features needed to unleash your robot's potential!

#1  
I haven't seen this error, but ARC is crashing every time I view the web page with a camera object, so it has delayed my work on making a custom web page. Not sure if it is just this one computer I have been developing on, or the camera (this did not happen when I previously played with the web server using an EZ-B camera, but it is happening when I use the Foscam snapshot URL or the web cam built into the laptop).

I have successfully used an iFrame to display the Foscam mjpeg stream instead of the camera object, so I will get back to making the custom buttons for controlling the camera pan/tilt and LEDs, and will deal with the crashing issue separately.

Alan
#2  
Hello Alan,

When I bring up the sample custom page it displays fine with either the ez-robot cam or the foscam. The streaming camera part of the page code didn't need to change at all. This is what works and did't need to change for either camera:

ez-camera data-controlname="Camera"
data-interval="50" Style="Width": 100%;
border: 3px solid #0000aa;"

Not sure this is the issue but thought I would mention it. Foscam displays streams fine in stock server page just kind of slow. Let me know what you come up with. As long as I select the proper foscam url in the ARC camera control and I can view the foscam video in ARC it displays fine in the example custom sever web page. Hope this maybe helps. Let me know when you get a chance. Thanks for your efforts ! Rick :):)
#3  
I am going to try on a different computer. This one has some other issues, so may well not be ARC related at all. It is just that this is my personal laptop so is convenient to work with while watching TV or otherwise not in my workshop or office. . I have desktops in both work spaces I can use instead, and my work laptop, although I try not to install much personal stuff on the work machine.

Alan
#4  
Alan,

I hear you about working on your laptop and watching tv ! Looking forward to seeing what you come up with. I haven't seen that error lately that I mentioned in a previous post. Aren't computers great ! Rick :):)
#5  
Alan,

Just wondering if you are using windows 10 or windows 7. I am using windows 7 and whichever camera (ez-robot or foscam) is selected in the ARC camera control, it works with the custom web server page with no modifications to the code for the page. Curious as to what you are finding? Does sound like a computer issue, either hardware or issues with windows 10 vs windows 7. Let me know what you find out? Thanks again.....Rick :):)
#6  
Hello Alan,

Just curious to here if you resolved the issue where ARC crashes when you open a custom server web page with a camera object in it? Sounds to me that it is most likely the computer. Take care and looking forward to hearing what you find out. Let me know if I can be of help as I have the same foscam camera that you have and it appears to work fine in the custom web server page and in the ARC camera control window.....Rick :):)
Login to post a comment