OPC Twin Edge Module
The OPC Twin module runs inside IoT Edge.
All OPC UA components use the OPC Foundation’s OPC UA reference stack as nuget packages and therefore licensing of their nuget packages apply. Visit https://opcfoundation.org/license/redistributables/1.3/ for the licensing terms.
OPC UA Client Services
The OPC Twin provides a IoT Hub device method API allowing the OPC Twin Microservice to invoke OPC UA server functionality on an activated endpoint. The Payload is transcoded from JSON to OPC UA binary and passed on through the OPC UA stack to the OPC UA server. The response is reencoded to JSON and passed back to the cloud service. This includes Variant encoding and decoding in a consistent JSON format.
Payloads that are larger than the Azure IoT Hub supported Device Method payload size are chunked, compressed, sent, then decompressed and reassembled for both request and response. This allows fast and large value writes and reads, as well as returning large browse results.
A single session is opened on demand per endpoint so the OPC UA server is not overburdened with 100’s of simultaneous requests.
Parametrization command line interface options & environment variables
The following list of module parametrization settings can be provided either as CLI options or as environment variables. When both environment variable and cli argument is provided,the latest will overrule the env variable.
site=VALUE
The site OPC Twin is assigned to
Type: string
Default: <not set>
EdgeHubConnectionString=VALUE
An IoT Edge Device or IoT Edge module connection string to use
When deployed in the iotedge module context, the environment variable
is already set as part of the container deployment
Type: connection string
Default: <not set> <preset by iotedge runtime>
Transport=VALUE
Upstream communication setting for edgeHub respectively IoTHub protocol
Type: string enum: Any, Amqp, Mqtt, AmqpOverTcp, AmqpOverWebsocket,
MqttOverTcp, MqttOverWebsocket, Tcp, Websocket.
Default: MqttOverTcp
BypassCertVerification=VALUE
Upstream communication setting for bypassing certificate verification
Type: boolean
Default: false
EnableMetrics=VALUE
Enable/Disable upstream metrics propagation
Type: boolean
Default: true
ApplicationName=VALUE
OPC UA Client Application Config - Application name as per
OPC UA definition. This is used for authentication during communication
init handshake and as part of own certificate validation.
Type: string
Default: "Microsoft.Azure.IIoT"
ApplicationUri=VALUE
OPC UA Client Application Config - Application URI as per
OPC UA definition
Type: string
Default: $"urn:localhost:{ApplicationName}:microsoft:")
ProductUri=VALUE
OPC UA Client Application Config - Product URI as per
OPC UA definition
Type: string
Default: "https://www.github.com/Azure/Industrial-IoT"
DefaultSessionTimeout=VALUE
OPC UA Client Application Config - Session timeout
as per OPC UA definition
Type: integer
Default: 0, meaning <not set>
MinSubscriptionLifetime=VALUE
OPC UA Client Application Config - Minimum subscription lifetime
as per OPC UA definition
Type: integer
Default: 0, <not set>
KeepAliveInterval=VALUE
OPC UA Client Application Config - Keep alive interval
as per OPC UA definition
Type: integer milliseconds
Default: 10,000 (10s)
MaxKeepAliveCount=VALUE
OPC UA Client Application Config - Maximum count of keep alive events
as per OPC UA definition
Type: integer
Default: 50
PkiRootPath=VALUE
OPC UA Client Security Config - PKI certificate store root path
Type: string
Default: "pki"
ApplicationCertificateStorePath=VALUE
OPC UA Client Security Config - application's
own certificate store path
Type: string
Default: $"{PkiRootPath}/own"
ApplicationCertificateStoreType=VALUE
OPC UA Client Security Config - application's
own certificate store type
Type: enum string : Directory, X509Store
Default: Directory
ApplicationCertificateSubjectName=VALUE
OPC UA Client Security Config - the subject name
in the application's own certificate
Type: string
Default: "CN=Microsoft.Azure.IIoT, C=DE, S=Bav, O=Microsoft, DC=localhost"
TrustedIssuerCertificatesPath=VALUE
OPC UA Client Security Config - trusted certificate issuer
store path
Type: string
Default: $"{PkiRootPath}/issuers"
TrustedIssuerCertificatesType=VALUE
OPC UA Client Security Config - trusted issuer certificates
store type
Type: enum string : Directory, X509Store
Default: Directory
TrustedPeerCertificatesPath=VALUE
OPC UA Client Security Config - trusted peer certificates
store path
Type: string
Default: $"{PkiRootPath}/trusted"
TrustedPeerCertificatesType=VALUE
OPC UA Client Security Config - trusted peer certificates
store type
Type: enum string : Directory, X509Store
Default: Directory
RejectedCertificateStorePath=VALUE
OPC UA Client Security Config - rejected certificates
store path
Type: string
Default: $"{PkiRootPath}/rejected"
RejectedCertificateStoreType=VALUE
OPC UA Client Security Config - rejected certificates
store type
Type: enum string : Directory, X509Store
Default: Directory
AutoAcceptUntrustedCertificates=VALUE
OPC UA Client Security Config - auto accept untrusted
peer certificates
Type: boolean
Default: false
RejectSha1SignedCertificates=VALUE
OPC UA Client Security Config - reject deprecated Sha1
signed certificates
Type: boolean
Default: false
MinimumCertificateKeySize=VALUE
OPC UA Client Security Config - minimum accepted
certificates key size
Type: integer
Default: 1024
AddAppCertToTrustedStore=VALUE
OPC UA Client Security Config - automatically copy own
certificate's public key to the trusted certificate store
Type: boolean
Default: true
SecurityTokenLifetime=VALUE
OPC UA Stack Transport Secure Channel - Security token lifetime in milliseconds
Type: integer (milliseconds)
Default: 3,600,000 (1h)
ChannelLifetime=VALUE
OPC UA Stack Transport Secure Channel - Channel lifetime in milliseconds
Type: integer (milliseconds)
Default: 300,000 (5 min)
MaxBufferSize=VALUE
OPC UA Stack Transport Secure Channel - Max buffer size
Type: integer
Default: 65,535 (64KB -1)
MaxMessageSize=VALUE
OPC UA Stack Transport Secure Channel - Max message size
Type: integer
Default: 4,194,304 (4 MB)
MaxArrayLength=VALUE
OPC UA Stack Transport Secure Channel - Max array length
Type: integer
Default: 65,535 (64KB - 1)
MaxByteStringLength=VALUE
OPC UA Stack Transport Secure Channel - Max byte string length
Type: integer
Default: 1,048,576 (1MB);
OperationTimeout=VALUE
OPC UA Stack Transport Secure Channel - OPC UA Service call
operation timeout
Type: integer (milliseconds)
Default: 120,000 (2 min)
MaxStringLength=VALUE
OPC UA Stack Transport Secure Channel - Maximum length of a string
that can be send/received over the OPC UA Secure channel
Type: integer
Default: 130,816 (128KB - 256)
Licensing
All OPC UA components use the OPC Foundation’s OPC UA reference stack as nuget packages and therefore licensing of their nuget packages apply. Visit https://opcfoundation.org/license/redistributables/1.3/ for the licensing terms.