# IO and Projector Control¶

The IOControl component allows reading the status of the general purpose digital inputs and controlling the digital general purpose outputs (Wiring). The outputs can be set to low or high, or configured to be high for the exposure time of every image. Additionally, the outputs can be configured to be high for the exposure time of every second image.

Note

The IOControl component is optional and requires the purchase of a separate license.

## Parameters¶

The IOControl component is called rc_iocontrol in the REST-API. The user can change the parameters via REST-API (REST-API interface) or GigE Vision using the DigitalIOControl parameters LineSelector and LineSource (Category: DigitalIOControl).

### Parameter overview¶

This component offers the following run-time parameters.

Table 23 The rc_iocontrol component’s run-time parameters
Name Type Min Max Default Description
out1_mode string - - ExposureActive Low, High, ExposureActive, ExposureAlternateActive
out2_mode string - - Low Low, High, ExposureActive, ExposureAlternateActive

This component reports no status values.

### Description of run-time parameters¶

out1_mode and out2_mode

The output modes for GPIO Out 1 and Out 2 can be set individually:

Low sets the ouput permanently to low. This is the factory default of Out 2.

High sets the output permanently to high.

ExposureActive sets the output to high for the exposure time of every image. This is the factory default of Out 1.

ExposureAlternateActive sets the output to high for the exposure time of every second image.

Figure Fig. 43 shows which images are used for stereo matching and transmission via GigE Vision in ExposureActive mode with a user defined frame rate of 8 Hz.

Fig. 43 Example of using the ExposureActive mode for GPIO Out 1 with a user defined frame rate setting of 8 Hz. The internal image acquisition is always 25 Hz. GPIO Out 1 is high for the exposure time of every image. A disparity image is computed for camera images that are send out via GigE Vision according to the user defined frame rate.

The mode ExposureAlternateActive is meant to be used when an external random dot projector is connected to the GPIO Out 1 or Out 2 of the rc_visard. A side effect of setting any output to ExposureAlternateActive is that the stereo matching component only uses images where the output that was configured ExposureAlternateActive is high, i.e. projector is on. The maximum framerate that is used for stereo matching is therefore halve of the frame rate configured by the user (see FPS). All other components like visual odometry, TagDetect and ItemPick use images where the output is low, i.e. projector is off. Figure Fig. 44 shows an example.

Fig. 44 Example of using the ExposureAlternateActive mode for GPIO Out 1 with a user defined frame rate setting of 8 Hz. The internal image acquisition is always 25 Hz. GPIO Out 1 is high for the exposure time of every second image. A disparity image is computed for images where Out 1 is high and that are send out via GigE Vision according to the user defined frame rate. In ExposureAlternateActive mode, images are always transmitted pairwise. One with Out 1 high for which a disparity image might be available and one with Out 1 low.

Note

In ExposureAlternateActive mode, an image with output high (i.e. with projection) is always 40 ms away from an image with output low (i.e. without projection), regardless of the user configured frame rate. This needs to be considered when synchronizing disparity and camera images without projection in this special mode.

The functionality can also be controlled by the digital IO control parameters of the GenICam interface (Category: DigitalIOControl).

## Services¶

The IOControl component offers the following services.

get_io_values

This service call retrieves the current state of the general purpose inputs and outputs. The returned time stamp is the time of measurement.

This service requires no arguments.

This service returns the following response:

{
"in1": "bool",
"in2": "bool",
"out1": "bool",
"out2": "bool",
"return_code": {
"message": "string",
"value": "int16"
},
"timestamp": {
"nsec": "int32",
"sec": "int32"
}
}

save_parameters

With this service call, the component’s current parameter settings are persisted to the rc_visard. That is, these values are applied even after reboot.

This service requires no arguments.

This service returns no response.

reset_defaults

Restores and applies the default values for this component’s parameters (“factory reset”).

This service requires no arguments.

This service returns no response.

Warning

The user must be aware that calling this service causes the current parameter settings for the IOControl component to be irrecoverably lost.