GigEVision write_memory error

Hi,
I encountered an error

failed to set double feature value ExposureTime to 130000, error: [ExposureTime] [ExposureTimeValConv] [ExposureTimeRawReg] GigEVision write_memory error (access-denied)

and would like to know what kind of condition will trigger GigEVision write_memory error?
I am trying to use arv_camera_set_float function to set the ExposureTime.