Camera time out

[anuppari]

I frequently get an error saying: "Failed to acquire image from UEye camera 'camera' (IS_TIMED_OUT)" My launch looks like this:

<include file="$(find ueye_cam)/launch/rgb8.launch" />
<param name="ueye_cam_nodelet/color_mode" type="str" value="mono8" />
<param name="ueye_cam_nodelet/image_width" type="int" value="752" />
<param name="ueye_cam_nodelet/image_height" type="int" value="480" />
<param name="ueye_cam_nodelet/auto_exposure" type="bool" value="False" />
<param name="ueye_cam_nodelet/auto_frame_rate" type="bool" value="False" />
<param name="ueye_cam_nodelet/pixel_clock" type="int" value="40" /> <!-- in MHz (max 40) -->
<param name="ueye_cam_nodelet/gain_boost" type="bool" value="False" />
<param name="ueye_cam_nodelet/auto_gain" type="bool" value="False" />
<param name="ueye_cam_nodelet/frame_rate" type="double" value="1.0" /> <!-- ignored if auto frame rate -->
<param name="ueye_cam_nodelet/exposure" type="int" value="10" /> <!-- in ms (ignored if auto exposure)-->

I'm using the uEye UI-1226LE-M-GL camera. Everything seems to work fine if I keep auto_exposure, auto_frame_rate and auto_gain on. However when I set them to specific values, it throws the time out error. If I plug the camera into a USB3.0 port, it works fine at the max frame rate, but the camera is a USB2.0 camera and should be able to support the max frame rate and pixel clock of 40 MHz in this slot.

To make sure its not the camera, I put the set the frame rate to 1 and very small exposure time in the above launch file, and yet I still get timeout errors.

[anqixu]

This error means that the underlying IDS driver is timing out when asked to pull an image from your camera. FYI in non-auto frame rate mode, the time out time is set to 2 * (1000ms / frame_rate) (search for eventTimeout in ueye_cam_nodelet.cpp), which is quite conservative.

Therefore, the cause of this error is most likely related to your hardware / OS-level software, e.g.:

• long USB cable
• poor quality USB cable
• poor quality connector on UEye cam (if hand-soldered)
• unreliable power throughput on USB bus
• overwhelmed USB bus
• high CPU load (e.g. hungry processes, constant RAM/swap thrashing, ...) causing IDS driver to time out

Here are some suggestions:

• try a different (shorter) USB cable
• try a different USB port
• if necessary, use a powered USB hub / active USB repeater
• remove unecessary USB devices
• check, and address, possible thrashing
• reduce CPU load
• try ueye_cam on a different computer
• run 'ueyedemo', set the desired camera parameters, and confirm that frames are frequently being dropped. Also check their "image informations" pop up dialog (the icon looks like a window with an information bubble), which might give you further hints on why frames are being dropped.