Start and sign into MES Operator
- Last UpdatedNov 28, 2025
- 3 minute read
Signing into MES Operator is a two-step process: first sign in to MES Operator, then you sign in to the entities where you will be view or enter data.
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On the Start menu, click the MES Operator tile.
The MES Operator logon window appears.

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In the Language list, click the language in which you want the login dialog box to appear.
You can select only those languages that are configured in the MES Client application. If you restart the application, the language setting resets to the default language, which is specified by the Display system parameter Default Language in MES Client.
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Enter your user name and password and click the green check mark button.
If you are not using a physical keyboard, click the Browse (...) button next to the User Name and Password boxes to display the on‑screen keyboard (see Understand the on-screen keyboard).
If the Password general system parameter in MES Client is set to Unique, only the password field will be visible.
Unless your user account has been set up for a job-based logon, after logging onto Operator, the Entity Logon dialog box appears. The entities that you have permission to work with are listed in the Available box.

If your user account has been set up for a job-based login, see Perform a job-based logon.
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To select the entities with which you want to work during this logon session, do one of the following:
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Select the entities in the Available box and then click the
single right arrow button to move them to the Selected box.
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To include all of the entities from the Available box in the Selected box, click the
double right arrow button.
You can also move entities from the Selected box back to the Available box using the
single right arrow button or
double right arrow button.
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When you have finished entering the entities to log on to in the Selected box, click the
Entity Logon button.
You are logged in to the entities that were in the Selected list. The entities in the Selected list are moved to the Currently Logged On to list.
If you decide you have logged on to the entities in error and want to log off of them, click the
Entity Logout.
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Click OK to close the Entity Login dialog box.
The first entity in the Currently Logged On to list is opened in Operator.