open_io_channel — Open and configure I/O channels.
open_io_channel opens and configures
transmission channels of an opened I/O device instance. The device
instance must have been opened by
open_io_device before and
is passed to
IODeviceHandle. The transmission channels
themselves are addressed by their names passed to
IOChannelName. Available names can be queried using
query_io_device with query parameter
'io_channel_name'. The channels can be configured by the
reference to each transmission channel is returned in
IOChannelHandle. If the instance of the channel is not
needed any more, it should be released and closed via the operator
close_io_channel. Besides, it will be closed automatically
when closing the associated device instance by
Having opened a transmission channel, values can be read and written
by the operators
write_io_channel on the channel.
An opened channel can be reconfigured by using the operators
Please check the directory 'doc/html/reference/io' for documentation about your specific I/O device interface, where all supported device specific parameters are listed.
This operator returns a handle. Note that the state of an instance of this handle type may be changed by specific operators even though the handle is used as an input parameter by those operators.
Handle of the opened I/O device.
HALCON I/O channel names of the specified device.
Default value: 
→(string / integer / real)
Default value: 
Handles of the opened I/O channel.
query_io_device (IODeviceHandle, , 'io_channel_names.digital_output', ChannelOutputNames) open_io_channel (IODeviceHandle, ChannelOutputNames, , , IOChannelHandle) write_io_channel (IOChannelHandle, 1, Status)
If the parameters are valid, the operator
open_io_channel returns the value 2 (H_MSG_TRUE). If necessary an
exception is raised. In this case, an extended error information may be
set and can be queried with the operator