Working with Protocol Adapters

About

The GE Digital APM OT Connect Adapter Service can support several different Protocol Adapter modules, depending on the configuration of the corresponding OT Source. These Protocol Adapters are used to connect to a specific Process Historian or a server that complies with an OPC specification.

The OT Connect Adapter Service will configure and start the Protocol Adapter matching the Type and Protocol Connection parameters configured on the OT Source on the following:

Service Start
When the OT Source is reconfigured

Capabilities

Different Protocol Adapters, and even in some cases different implementations or versions of a Process Historian or OPC Server can support a variety of different capabilities when querying or subscribing to data.

The supported capabilities are listed on the table below:


Name	Supported action
LastReading	Query the OT Source for the last good Reading for a Tag.
StartToEndReadings	Query the OT Source for all Readings between a Start and End time.
SubscribeReadings	Establish a subscription to new Readings for a Tag, which can be used to update Health Indicators or trigger Policy Instances unsolicited.
BeforeEndReadings	Query the OT Source for a specified number of readings before an End time.
SubscribeReadings	Subscribe to a Tag for updated Readings with a new Timestamp or Value.

The Capabilities of an OT Source are reported as part of the Connection Status.

Simulation

The Simulation Protocol Adapter is provided for testing and exploration. Rather than connecting to an actual process historian, it provides simulated tag metadata and Readings for all Capabilities.

ProtocolConnection

The Simulation Protocol Adapter is not configurable.

OPC-HDA

The OPC-HDA Protocol Adapter can connect to an OPC Classic HDA 1.20 server.

Important: The OPC-HDA Protocol Adapter does not support remote connections. The OPC-HDA server must be installed on the same server, preferably running under the same user account as the Adapter Service.

Vendors have implemented different elements of the specification, so it is important to review the Connection Status or OT Source Capability Utility report to understand what Capabilities are available from the server you want to integrate with GE Digital APM.

A fully supported OPC server can provide the following:

LastReading
SubscribeReadings
GetStartEndReadings

ProtocolConnection

The OPC-HDA ProtocolAdapter requires the ProgId to be configured.

If the correct ProgId is not provided, the ProtocolAdapter will log an exception report on all available OPC-HDA ProgIds on the server on startup.

OSI Pi

The OSI Pi Protocol Adapter can connect to Pi Server 2010 and later through the Asset Framework (AF) Protocol. This allows OT Connect to support Pi without an intervening OPC server. It requires the PI AF Client be installed on the OT Connect Process Data server. It is recommended to use this adapter to connect to OSI Pi servers whenever possible, as the AF protocol offers improved security, performance, and reliability.

The OSI Pi Protocol Adapter offers the following Capabilities:

LastReading
SubscribeReadings
GetStartEndReadings
GetBeforeEndReadings

Configure the OSI Pi Protocol Adapter

Install the PI AF Client. For information on installing the Pi AF client, refer to the OSIsoft documentation.
Configure the OT Source.

Table 1. Connection Details
Host Name	Hostname or FQDN of the target server. The host name must be configured in the System Explorer exactly as it is entered here.
User Name	Windows user configured with a Pi mapping.
Password	Windows password.

GED Historian

The GED Historian Protocol Adapter can connect to GED Historian 4.0 and later through the Client Access API. This allows OT Connect to support the GED Historian without an intervening OPC server. It requires the Client Access Assemblies to be installed on the OT Connect Process Data server.

It is recommended to use this adapter to connect to the GED Historian servers whenever possible, as the Client Access API offers improved security, performance, and reliability.

The GED Historian Protocol Adapter offers the following Capabilities:

LastReading
SubscribeReadings
GetStartEndReadings
GetBeforeEndReadings

Note: Health Indicators, Triggered Policies, and Last Reading are only supported on GED Historian through the GED Historian Protocol adapter. These capabilities are not available through OPC.

Configure the GED Historian Protocol Adapter

Install the Historian Client Tools by selecting the Client Access Assemblies. For information on installing the Historian Client Tools, refer to the GE Digital Historian documentation. Other features are not required and the Historian Data Archiver can be on another server.
Configure the OT Source.

Table 2. Connection Details
Host Name	Hostname or FQDN of the target server. The host name must match exactly with the name that was provided when installing the target historian.
User Name	Windows user with iH Readers membership on the Process Historian server.
Password	Windows password.

OPC-DA

The OPC-DA Protocol Adapter can connect to OPC Classic DA servers installed on the same server as the OT Connect Adapter Service.

Vendors have implemented different elements of the specification. So, it is important to review the Connection Status or OT Source Capability Utility report to understand what Capabilities are available from the server that you want to integrate with GE Digital APM.

A fully supported OPC server can provide the following capabilities:

LastReading
SubscribeReadings

ProtocolConnection

The OPC-DA ProtocolAdapter requires the ProgId to be configured.

If the correct ProgId is not provided, the ProtocolAdapter will log an exception report on all available OPC-DA ProgIds on the server on startup.