SAMPLE cannot be represented as a DATA_SET

[robot-ranger]

I was expecting to be able to represent a sample as a dataset, but the agent complains about not being able to convert to a double:

SHDR:

[11]: DATAITEMS SHDR: 2024-11-24T00:10:16.033491Z|mxi_m001_target_q|j0=-105.939 j1=-64.723 j2=-129.918 j3=-90.387 j4=128.378 j5=-21.754

Agent log:

2024-11-24T00:10:16.879811Z (0x0000007fa7fff000) [warning] Connector::reader->Connector::parseSocketBuffer->Connector::processLine->ShdrAdapter::processData->DataItemMapper.ShdrTokenMapper.operator->DataItemMapper.ShdrTokenMapper.mapTokensToDataItem->zipProperties: Cannot convert value for data item id 'mxi_m001_target_q': j0=-105.939 j1=-64.723 j2=-129.918 j3=-90.387 j4=128.378 j5=-21.754 - (VALUE): cannot convert string 'j0=-105.939 j1=-64.723 j2=-129.918 j3=-90.387 j4=128.378 j5=-21.754' to double

device.xml:

<?xml version="1.0" encoding="UTF-8"?>
<MTConnectDevices
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns="urn:mtconnect.org:MTConnectDevices:2.3"
  xsi:schemaLocation="urn:mtconnect.org:MTConnectDevices:2.3 https://schemas.mtconnect.org/schemas/MTConnectDevices_2.3.xsd">
	<Header deviceModelChangeTime="2022-06-17T16:33:21.188094Z" creationTime="2013-04-02T03:40:04Z" assetBufferSize="1024" sender="localhost" assetCount="0" version="2.3" instanceId="1" bufferSize="131072"/>
	<Devices>
		<Device name="machine_1" id="mxi_m001" uuid="mxi_m001">
			<DataItems>
				<DataItem id="mxi_m001_target_q" name="target_q" type="ANGLE" representation="DATA_SET" category="SAMPLE" subType="COMMANDED"/>
			</DataItems>
		</Device>
	</Devices>
</MTConnectDevices>

the use case here is a digital twin of a 6-axis robot. the joint angles are provided from the robot.

It seems to work if i change category="EVENT" instead of SAMPLE. technically type="ANGLE" is not an EVENT, but the agent doesnt seem to care about that?

Is there a better way to model this?

[wsobel]

I’ll need to check the code. I’m not sure if we’ve done a sample as a data set as of yet. It should override he sample category conversion, but I’m not sure what takes precidece. You’re right this is not the behavior desired.

…

Sent from my iPad

[robot-ranger]

what is the functional or parsing difference between a sample and an event? or are they truely just 'categories'?

[wsobel]

They are just categories, but a sample is fixed as a floating point number where as an event can have a controlled vocabulary or a string value. Representation is handled as a special case when parsing. I may have inverted the checks on the observation factory method that messed this up. I’ll check tomorrow. The code is fairly complex handling all the type construction and checks.

[robot-ranger]

SAMPLE as DATA_SET Works great now! 👍