query_io_device — Query information about channels of the specified I/O device.
query_io_device( : : IODeviceHandle, IOChannelName, Query : Result)
The operator query_io_device returns information about
transmission channels of a specified I/O device. The handle to the
I/O device is passed to in IODeviceHandle, whereas the
channels are addressed by IOChannelName. The desired
information about the I/O channels is specified via Query.
A list of all supported channel names is usually returned when passing
'io_channel_name' to Query while the input
parameter IOChannelName is ignored.
Please check the directory doc/html/reference/io
for documentation about your specific I/O device interface, where
all supported channel-specific parameters are listed.
IODeviceHandle (input_control) io_device → (handle)
Handle of the opened I/O device.
IOChannelName (input_control) string(-array) → (string)
Channel names to query.
Query (input_control) string-array → (string)
Name of the query.
Default value: 'param_name'
List of values: 'io_channel_names', 'param_name'
Result (output_control) string-array → (string / integer / real)
List of values (according to Query).
* Select a suitable i/o device interface of name IOInterfaceName
query_io_interface (IOInterfaceName, 'io_device_names', DeviceNames)
open_io_device (IOInterfaceName, DeviceNames[0], [], [], IODeviceHandle)
query_io_device (IODeviceHandle, [], 'io_channel_names.digital_input', \
ChannelInputNames)
open_io_channel (IODeviceHandle, ChannelInputNames[0], [], [], \
IOChannelHandle)
read_io_channel (IOChannelHandle, Value, Status)
If the parameters are valid, the operator
query_io_device 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 get_extended_error_info.
Foundation