We provide an API via Web-Service that can read and write tag values. To access the tags, a login is required for solution users. You can directly access this API through HTTP (REST API) connecting with a runtime system. 

This page presents information about how to use the WebAccess REST API.

On this page:

Contract Methods Using Rest API

The Web-Server URLs have the following URL syntax "http://<IPAddress>/<ProductVersion>/WebAccessService.svc/<ContractMethod>" where the contract methods are described below.

GetVersion() 

Gets the service version.

Syntax:

  1. Method: GET
  2. URL Example: http://localhost/fs-8.1/WebAccessService.svc/GetVersion
  3. Response Example:
{"GetVersionResult":2}


Login(string userName, string password)

Logs in project user. Parameters:

  • userName: User No case.
  • password: Password. Case

Syntax:

  1. Method: GET
  2. URL Example: http://localhost/fs-8.1/WebAccessService.svc/Login?userName=guest password=test.
  3. Response Example:
{
"LoginResult":
	{
	"Handle": 2,
	"Status": ""
}
}
Returns the connection handle (whether >= 0) or error code (whether < 0).


Logout(int handle)

Logs out project user. Parameters:

  • handle: Connection. This value was returned by Login method.

Syntax:

  1. Method: GET
  2. URL Example: http://localhost/fs-8.1/WebAccessService.svc/Logout?handle=1.
  3. Response Example:
{
"LogoutResult": 0
}
0: OK, 1: Invalid connection handle.


ReadObject(int handle, string objectName)

Reads value from specified object. Parameters:

  • handle: Connection. This value was returned by Login method.
  • objectName: Object (Tag) Name.

Syntax:

  1. Method: GET
  2. URL Example: http://localhost/fs-8.1/WebAccessService.svc/ReadObject?handle=1&objectName=tagExample.
  3. Response Example:
{
"ReadObjectResult":
	{
	"ObjectName": "tagExample",
	"Quality": 64,
	"UtcTimeStamp": "11/29/2019 17:33:47",
	"Value": "0"
}
}
Returns Value of the object.


ReadObjects(int handle, IList<string> objectNames)

Read value from a list of objects. Parameters:

  • handle: Connection. This value was returned by Login method.
  • objectNames: Objects (Tags) Name.

Syntax:

  1. Method: POST
  2. URL Example: http://localhost/fs-8.1/WebAccessService.svc/ReadObjects .
  3. Body Example:
{
"handle" : 1,
"objectNames" :["tagExample1", "tagExample2"]}

4. Response Example:

{
"ReadObjectResult":
	{
	"ObjectName": "tagExample1",
	"Quality": 192,
	"UtcTimeStamp": "02/12/2021 11:13:38",
	"Value": "20"
},
{
 	"ObjectName": "tagExample2",
	"Quality": 192,
	"UtcTimeStamp": "02/12/2021 11:13:36",
	"Value": "10" 
}
}
Returns Value of the objects.


WriteObject(int handle, ObjectItem item, bool force)

Write value to specified object. Parameters:

  • handle: Connection. This value was returned by Login method.
  • item: Object (Tag) Name.
  • force: Flag to force value.

Syntax:

  1. Method: POST
  2. URL Example: http://localhost/fs-8.1/WebAccessService.svc/WriteObject.
  3. Body Example:
{
	"handle" : 1,
	"item" : {
   	"ObjectName": "tagExample2",
	"Quality": 192,
	"UtcTimeStamp": "02/12/2021 11:13:36",
	"Value": "2"  
	}
	"force": false}

4. Response Example:

"WriteObjectResult": true
Returns Flag indicating success or fail.


WriteObjects(int handle, IList<ObjectItem> items, bool force)

Write value to specified object. Parameters:

  • handle: Connection. This value was returned by Login method.
  • items: Object (Tag) Names.
  • force: Flag to force value.

Syntax:

  1. Method: POST
  2. URL Example: http://localhost/fs-8.1/WebAccessService.svc/WriteObjects.
{
	"handle" : 1,
	"itens" : 
	[{
   	"ObjectName": "tagExample1",
	"Quality": 192,
	"UtcTimeStamp": "02/12/2021 11:13:36",
	"Value": "2"  
	},
	{
   	"ObjectName": "tagExample2",
	"Quality": 192,
	"UtcTimeStamp": "02/12/2021 11:13:36",
	"Value": "13"  
	}],
	"force": false}

4. Response Example:

"WriteObjectsResult": [true, true]
Returns Flag indicating success or fail.


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