Tech Note 115
Overview of the InTouch 7.0 Windows NT Services
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Topic#: 000723 Created: October 1998
A service is a process in Windows NT that performs a specific system function. Services can be
configured to automatically start up when the computer on which the application is installed starts up. Services are also started without compromising Windows NT’s security system. Wonderware®
introduced running the FactorySuite™ components as services in the FactorySuite 2000 release. This
Tech Note discusses the Windows NT services for InTouch™ 7.0, which is part of the FactorySuite
2000.
InTouch 7.0 consists of four Windows NT services: Windows NT Services Default Location
Wonderware Logger C:\Program files\Factorysuite\Common\WWlogsvc.exe Wonderware SuiteLink C:\Program files\Factorysuite\Common\Slssvc.exe Wonderware NetDDE Helper C:\Program files\Factorysuite\Common\Wwnetdde.exe Wonderware WindowViewer C:\Program files\Factorysuite\Intouch\View.exe
Note For more information the Windows NT services for the FactorySuite components, see the online Wonderware FactorySuite Administrator’s Guide.
Why Use Services?
Here are the reasons Wonderware chose to introduce Windows NT services to InTouch 7.0 and the other FactorySuite 2000 components:
1. Operator Log on and Log off. During normal plant operations, the operators will usually log on and log off the Windows NT operating system between work shift changes. When WindowViewer runs as a Windows NT service, it will continue to run even as different operators log on and off the computer during shift changes. For example, after one operator logs off the system and another one logs on, WindowViewer will continue to log historical data, gather alarm information, process scripts, act as an I/O server, and write values as an I/O client.
2. Power loss. If the electrical power is disrupted, it can take the plant operators some time before the plant operations resume normal operations. Most disaster recovery plans require that
essential computer systems start immediately after the electrical power is restored. Microsoft Windows NT Workstations and Windows NT Servers can restart automatically after the power is restored. Since the FactorySuite 2000 software is run as a set of Windows NT services, this will ensure that your vital systems can begin running immediately without compromising the Windows NT security.
3. Continuous operations. The modern plant places resource efficiency as a primary concern. To achieve this level of throughput many plants use continuous operations. When the FactorySuite components run as Windows NT services, it allows a plant to operate continuously 24 hours, seven days a week.
Creating a “Master” User Account
When the Windows NT operating system starts up a service, it runs in a user context called the local
system account. Thus, when the computer starts up, every Windows NT service that is configured to
automatically start will run under this local system account. When you log onto the Windows NT operating system with your own account and you launch an application, it will run under your user account.
However, the local system account has very few privileges within the Windows NT security system and it’s no guarantee that the users who log onto the system will have the rights to run the FactorySuite services, including the InTouch 7.0 services. This includes actions such as accessing files, exchanging data between other programs and services and modifying the registry. The FactorySuite requires that the user account have a higher access level in the Windows NT security system than the local system account so that the services can do these types of actions.
Thus, we recommend that you create a “master” user account for the FactorySuite. (A good name for the user account is “wwservices”.) This master account should have Administrative privileges on the local computer so that it has the rights to start up the FactorySuite services. Then, during the FactorySuite installation when the FS2000 Common Components dialog box appears, enter the node name of the local computer—not the domain name—along with the user name and password of the master account.
Note When discussing the Windows NT services, you may hear the term impersonation account used in place of the master account. An impersonation account is the User/Group account that provides access to the restricted resource “area” of your site or server. In Windows NT, this is called the NT User/Group Account, which must be set up by the System Administrator.
Later, when someone logs onto the computer and starts up a FactorySuite component (such as WindowViewer), the component’s services will run under the master account instead of his user account, thus ensuring that the user will have the necessary privileges to start up the FactorySuite service.
Specifying the “Master” Account After Installing the FactorySuite
Enter the machine name and the user name and password of the master account, as shown in the example above.
Configuring the InTouch 7.0 Services
The InTouch services, Wonderware Logger, Wonderware SuiteLink and Wonderware NetDDE Helper, are installed and configured during the FactorySuite 2000 installation to automatically start up. However, if you want to configure WindowViewer to automatically start up as a Windows NT service, then follow these two simple steps:
Manually Installing or Removing a Service
Normally, the FactorySuite’s Windows NT services are automatically installed during the FactorySuite installation procedure and they are removed by double-clicking the Control Panel’s Add/Remove Programs icon. However, if you need to manually install or remove a FactorySuite 2000 Windows NT service, we recommend that you do the following:
Select Run from the Start menu or open an MS-DOS Command Prompt window.
To install a Windows NT service (example, Wonderware WindowViewer), enter this command:
“C:\Program Files\FactorySuite\InTouch\view.exe” -install
To remove a Windows NT service, enter this command:
“C:\Program Files\FactorySuite\InTouch\view.exe” –remove
Both commands are examples that install and remove the Wonderware WindowViewer service. The pathname will include the \Common directory instead of the \InTouch directory for the other FactorySuite services.
Note If you enter the command in the Run dialog box, be sure to enclose the command with double quotes (“ “) as shown above if the file path includes spaces (example, “Program Files”). Also, be aware that if you remove a service, Windows NT will stop the service first and then remove it. However, removing a service will not delete the application’s .Exe file.
Stopping and Starting WindowViewer as a Service
Assuming that the Wonderware WindowViewer service is configured by default to automatically start up, you can stop or start up the WindowViewer service simply by shutting the computer down or by restarting it. But there are also a few other ways to stop or start up the Wonderware WindowViewer service, which are:
2. Highlight Wonderware WindowViewer from the Service list and click the Start or Stop button. Or
3. Start up WindowMaker and select the Runtime! option from the menu bar. Or
4. From the InTouch Application Manager, launch WindowViewer. Or
5. Select Run from the Start menu or open an MS-DOS Command Prompt window. To start the Wonderware WindowViewer service, type in this command:
Net Start View
To stop the Wonderware WindowViewer service, type in this command: Net Stop View
Note Any changes to the master account must be done during installation of InTouch 7.0 or by running the Wonderware Service User program, Wwuser.exe. (See the previous section, “Specifying the Master Account After Installing the FactorySuite”.) Do not change the “Log On As:” properties on the Service dialog box that’s shown in the next section. Also, if the Wonderware WindowViewer service is configured to start up automatically, when the system restarts the last InTouch application that was referenced by the InTouch Application Manager will be launched. When editing more than one InTouch application, if you lose power or restart the system then the wrong application may start up.
3. Select the appropriate radiobutton for the Startup Type: Automatic, Manual or Disable. Then click the OK button. (We recommend that you keep the default options under the Log On As: section of the dialog box.)
Dependencies Between the InTouch 7.0 Services
When a service is installed, a list of dependencies is provided to the Windows NT operating system. If a service depends on other services starting first, before the service can be launched, Windows NT checks to make sure that the other services are running before allowing the service to start. Depending on your requirements for running WindowViewer, you should be aware of the following dependencies:
The Wonderware NetDDE Helper service must be running if you plan to use the Distributed Alarming or Distributed History feature or if you intend to access Network DDE data. The Wonderware NetDDE Helper service also depends on both the Network DDE and Network DDE DSDM services being installed and configured for either Manual or Automatic startup. During installation, the Wonderware NetDDE Helper service will be configured for Manual startup, which means that WindowViewer will automatically start this service on boot.
If you want to store any messages or errors while WindowViewer is running, you must make sure that the Wonderware Logger service installed. However, both the Wonderware SuiteLink and Wonderware Logger services should be installed and configured to run in Automatic startup as part of the
FactorySuite common installation.
Note on Network DDE and Logging Off Windows NT
When you log off the Windows NT operating system, it sends the control log off messages, wm_close and wm_terminate, which close all applications that are running under the desktop context. (See the previous section, “Services Running in Desktop Context Versus System Context”.) Microsoft Network DDE that has been installed as its default configuration will “listen” for these log off messages, and if received, it will terminate its open network connections. While you log off the system, Network DDE will not permit any new connections to be made.
However, what the Wonderware NetDDE Helper service will do is listen and capture the log off messages for Network DDE, which will preserve the Network DDE connections. This means that while you are logged off, Network DDE will go ahead and allow the new connections to be made—thus, earning the service name “Wonderware NetDDE Helper”!
Troubleshooting the InTouch 7.0 Services
Here are some common problems and solutions that Wonderware Technical Support has found when installing or running the InTouch 7.0 services:
Error “One or more services failed to start…”
If you run into this error, from the Start menu select Programs/Administrative Tools
(Common)/Event Viewer. The Event Viewer – System Log window will appear in which it lists a file consisting of informational messages, warnings or errors that may have occurred during the start up of any Windows NT services:
Note Keep in mind that if you choose Yes to run WindowViewer as a desktop application, when you log off the system, WindowViewer will close. It will not continue to run as a service since it was never originally started as a service. This means that after you log off, your InTouch application will not continue to run and collect historical data, display alarms or process scripts. To allow your InTouch application to continue running as a service, you will need to log back on and follow one of the methods in the previous section, “Stopping and Starting WindowViewer as a Service”.
InTouch 7.0 Services Fail to Install or Start Up
During the FactorySuite installation, if the InTouch 7.0 services fail to install or start up after the installation, then the cause of this problem is probably related to the Windows NT security account or other related issues. Follow these steps if you find that the InTouch 7.0 services have failed to install or to start up:
1. Bring up the Windows NT User Manager window and create a new “master” user account (example, wwservices). This user account must have Administrative privileges on the local computer in order to start up a FactorySuite component as a service. If you do not see your computer’s node name in the domain list, then manually type in the node name. (See the previous section, “Creating a ‘Master’ User Account”.)
Note If your computer’s node name is longer than 14 characters or if you have underscore characters (_) or dashes (-) in the node name, then you should modify the node name to something equal to or less than 14 characters without underscores or dashes.
2. During the FactorySuite installation when you are prompted to enter the domain name, type in the node name of your computer, not the domain name. Then type in the username that was created in step 1 (example, wwservices) and the password.
If you have already installed the FactorySuite, you can still specify the domain name, user name and password by running the Wonderware Service User program, Wwuser.exe, from the
directory C:\Program files\Factorysuite\Common 3. Reboot your computer.
You may now log onto your network domain with any valid user account. Even if your domain goes down, it will not affect your InTouch application that is running on the local computer.
M. McCulty
The Tech Note is published occasionally by Wonderware Technical Support. Editors: Sabrina Abercromby and Kelly Hauser; Publisher: Wonderware Corporation, 100 Technology Drive, Irvine CA 92618. There is also technical
information on our software products at Wonderware Technical Support, our WonderFax fax-on-demand system at (949) 450-5050, and the Comprehensive Support Knowledge Base.
