The purpose of this article is to be a reference for OPC UA collector part of the full Data Collection Module documentation
Prerequisite: A Starter package (SiteManager + accounts)	Other sections in DCM: Getting started Guides Examples Frequently asked questions Troubleshooting

The Collectors (array of objects, mandatory ) list elements contains the following fields:

Function	Type	Importance	Description
CollectorName	string	mandatory	Unique name (within this confguration file) of a device to collect data from. (This is the name used in the agent configuration). Follows the normal rules for names.
CollectorDesription	string	optional	Description of this collector. For your use, no system function)
CollectorIPAddr	string	optional	Default IP address (or DNS name) for the device to be polled. The agent Target IP address will take precedence over this.
CollectorPortno	integer > 0 and < 65535	optional	Default port number for the device to be polled. The agent Target Port number will take precedence over this. If neither CollectorPortno , nor agent Target Port Number is specified, the appropriate port will be used, depending on the Protocol parameter value.
Alias	string	optional	This is the CollectorName of another collector, from which, all the parameters (expect CollectorName , CollectorDescription , CollectorIPAddr and CollectorPortno ) are copied from. An alias cannot refer to another alias.
Protocol	string-enum	mandatory	The protocol used to collected data. Currently 3 possible values exists: "OPC-UA/TCP", "Modbus/TCP", "Http/GET" and "Simulator".
ConnectRetryMin	integer > 0	mandatory	Minimum number of seconds before trying to reestablish a connection to the device being sampled. An exponential backoff algorithm is used to retry connection establishment, starting after ConnectRetryMin and increasing to ConnectRetryMax.
ConnectRetryMax	integer > 0	mandatory	Maxumin number of seconds before trying to reestablish a connection to the device being sampled.
OPCUAAccess	Object	optional	Collection of parameters needed to access a given OPC-UA/TCP server.
SamplePoints	Array of objects	mandatory	List of samples to be collected, possibly aggregated and stored in the Store'n'Forward database.

Example of OPCUAaccess object

"OPCUAAccess" : {
	"OPCUASecurityPolicy" : "none",
	"OPCUAUserTokenType" : "anonynmous",
	"OPCUATimeStampPolicy" : "dcm"
	}

Samplepoint items

The SamplePoints objects contains the following elements:

Function	Type	Importance	Description
SampleName	string	mandatory	Name of this sampled value (sometimes called a tagname). Follows the normal rules for names.
SampleDescription	string	optional	is a text description of this sample value.
SampleUnit	string	optional	is a description of the unit of messurement for this sample.
SampleGroup	string	optional	designates (in some datasrvs) that all samplepoints in that group should be handled (displayed) together. The DCM system itself places no meaning on this group affiliation.
SamplesSaved	integer > 0	mandatory	is the number of values collected that is saved as minimum in the Store'n'Forward database. If set to 0 the Samplepoint isn't stored in the S'n'F database and thus not delivered to cloud, but can be used for aggregations.
OnlySaveOnChanged	bool	optional	control if new sample values should only be saved to the store-and-forward database if the values have changed since last sample. If not set, it is false.
SampleDataType	string-enum	mandatory	The type of data collected. The possible values are: "bool" (1 bit), "sbyte" (8 bit signed), "byte" (8 bit unsigned), "int16" (16 bit signed), "uint16" (16 bit unsigned), "int32" (32 signed), "uint32" (32 bit unsigned), "int64" (64 bit signed), "uint64" (64 bit unsigned), "float" (32 bit), "double" (64 bit), "string" (variable text up to 24575 bytes. Includes terminating NUL), "data" (variable variable data up to 24575 bytes).
SampleLowerLimit	integer/double	optional	The lower limit for the collected data. If the collected data value is less than SampleLowerLimit it is evaluated inaccordance to SampleLimitDiscard and SampleLimitAlarm.
SampleUpperLimit	integer/double	optional	The upper limit for the collected data. If the collected data value is more than SampleUpperLimit it is evaluated inaccordance to SampleLimitDiscard and SampleLimitAlarm.
SampleLimitDiscard	bool	maybe-optional	Controls if a sample limit violation results in the sample value being discarded. Mandatory if either SampleLowerLimit or SampleUpperLimit is present.
SampleLimitAlarm	bool	maybe-optional	Controls if a sample limit violation generates an alarm. Mandatory if either SampleLowerLimit or SampleUpperLimit is present.
OPCUAObject	Object	maybe-optional	Description of how to address a specific OPC-UA object, when collecting values from it. Mandatory if the protocol type is "OPC-UA/TCP".

OPC UA samplepoint

The OPCUAObject object contains the following fields:

Function	Type	Importance	Description
NodeIdNameSpaceIndex	integer >= 0 and < 65535	mandatory	This is the OPC-UA namespace index (ns value in OPC UA tools).
NodeIdType	string-enum	mandatory	This is the OPC-UA NodeID type. (ID type of the tag) The possible values are: "numeric", "string", "guid" or "bytestring".
NodeIdNumeric	integer	maybe-optional	This is OPC-UA NodeID numeric value. Only mandatory if the value of NodeIdType is "numeric".
NodeIdString	string	maybe-optional	This is OPC-UA NodeID string value. Only mandatory if the value of NodeIdType is "string".
NodeIdGuid	string	maybe-optional	This is OPC-UA NodeID GUID value. Only mandatory if the value of NodeIdType is "guid". The format is hex-digits with hyphens enclosed in curly brackets: {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX} (38 characters).
NodeIdByteString	string	maybe-optional	This is OPC-UA NodeID byte string value. Only mandatory if the value of NodeIdType is "bytestring". The format is hex-digitis. Must not be an empty string and must contain a even number of hex digits.
OPCUASampleInterval	integer >= 0, mandatory	The number of seconds between each sample of this OPC-UA object. If the interval is 0, only eventdriven polling is used.
OPCUATimeStampPolicy	string-enum	optional	The timestamp to mark this sample data with. Currently 3 possible values exists: "source", "server" or "dcm". If this field is not present the OPCUATimeStampPolicy filed from the OPCUAAccess object, this sample belongs to, will be used instead.

Example of collector with OPCUAAccess, Samplepoints and OPCUAObject objects:

{
 "CollectorName": "OmronOPCUA",
 "CollectorDescription": "Example Omron NX1 with OPC-UA Server",
 "Protocol": "OPC-UA/TCP",
 "ConnectRetryMin": 2,
 "ConnectRetryMax": 240,
 "OPCUAAccess": {
  "OPCUASecurityPolicy": "none",
  "OPCUAUserTokenType": "anonynmous",
  "OPCUATimeStampPolicy": "dcm"
  },
 "SamplePoints": [
 {
 "SampleName": "Temp1",
 "SampleDescription": "B1 Potmeter",
 "SamplesSaved": 1000,
 "SampleDataType": "int16",
 "SampleLimitDiscard": true,
 "SampleUpperLimit": 8100,
 "SampleLowerLimit": 0,
 "SampleLimitAlarm": false,
 "OPCUAObject": {
  "NodeIdNameSpaceIndex": 4,
  "NodeIdType": "string",
  "NodeIdString": "Analog1",
  "OPCUASampleInterval": 4
  }
  }
 ]
}

Example of collector for OPC UA server on Siemens PLC

{
  "CollectorDescription": "Example with Siemens PLC w/OPC-UA Server",
  "CollectorName": "Test2OPCUA",
  "ConnectRetryMax": 240,
  "ConnectRetryMin": 10,
  "OPCUAAccess": {
   "OPCUASecurityPolicy": "none",
   "OPCUATimeStampPolicy": "dcm",
   "OPCUAUserTokenType": "anonynmous"
   },
  "Protocol": "OPC-UA/TCP",
  "SamplePoints": [
 {
  "OPCUAObject": {
  "NodeIdNameSpaceIndex": 3,
  "NodeIdString": "\"DB_MRUSim\".\"Out\"",
  "NodeIdType": "string",
  "OPCUASampleInterval": 1
 },
  "SampleDataType": "double",
  "SampleDescription": "AHC curve",
  "SampleName": "AHC",
  "SamplesSaved": 10
  }
 ]
}

See complete OPC UA examples here:
Basic OPC UA config

data collection data collector data collection module dcm opc opc ua date 20200903 360

Creation date: 11/12/2019 14:08 (skr@secomea.com) Updated: 14/04/2021 08:31 (jmp@secomea.com)

OPC UA collector

Prerequisite:

Samplepoint items

OPC UA samplepoint