While many machine vision applications manage with fixed distances, lighting conditions and fields of view, there are also applications for GigE Vision and USB Vision cameras that require different magnifications, focal points or apertures. Opto Engineering, for example, offers two motorized lens series for this type of application.

• ENMT series with fixed focal length and motorized focusing and aperture mechanism and

• MZMT series, 12x or 5X stepless macro zoom lenses with motorized control.

The advantage of these solutions is that they only require a programming interface from the camera to the host PC and therefore no additional USB port, which is then free for other purposes.

First of all, a camera needs an RS232 port. With firmware version 2.24.975.0, this is supported by the BVS CA-GX0 (incl. POE), BVS CA-GX2 and BVS CA-SF camera families. The MTCN001 adapter box from Opto Engineering also converts RS232 to RS485. The signals are then sent to the motion control box. MTDV3CH-00A1 is a motion controller for three two-pole stepper motors: Movements can be controlled both manually and via PC / PLC and support relative or absolute positions, or movement to a specific aperture, magnification or to a specific working distance. Connect the adapter box to the Hirose port of the camera using the cable KS-HR12S-HR12PP XX.X No.1520513. Then connect the RS485 adapter box to the motion controller. The following commands are supported by the Impact Acquire SDK interface:

• mvStepperFirmwareVersion:

• mvStepperAutoSave Position: [True, False]

• mvStepperMotorSelector: [Zoom, Focus, Iris]

  • mvStepperMoveToHome()

  • mvStepperSteps: [min..max]

  • mvStepperMoveSteps()

  • mvStepperPosition: [min..max]

  • mvStepperMoveToPosition() mvStepperStop()

  • mvStepperCurrentPosition: [min..max]

  • mvStepperStatus: mvStepperSpeed: [min..max]

  • mvStepperAccerleration: [min..max]

• mvStepperMoveToHomeAll()

• mvStepperStopAll()

• mvStepperPositionSetSelector: [0..]

  • mvStepperLoadPositionSet()

  • mvStepperSavePositionSet()

• SelectOptoEngineeringStepper under "mv Serial Interface Mode".

• The selected motor can be moved to the desired position using "mv Stepper Move ...".

• Up to 100 predefined positions can be loaded or saved using "mv Stepper Position Set Selector".

Figure 1: mv Serial Interface Control

The properties of the "mv Serial Interface Control" for RS232 are Balluff specific but appear in the XML file of the camera according to the GigE Vision Standard and SFNC (Standard Feature Naming Convention). This allows this feature to be used in third-party software and applications, as shown in the following example of HALCON image acquisition.

Figure 2: mv Serial Interface Control with third-party libraries

Supported series are:

• ENMT series with fixed focal length and motorized focus and iris mechanism

• MZMT series, 12x or 5X stepless macro zoom lenses with motorized control

All BVS CA-SF cameras and all BVS CA-GX0 / BVS CA-GX2 cameras with sensor diagonals up to 2/3" (4/3" for the 5x macros).