Force Mode

Precautions

Forcing input and output values in a running controller can have serious consequences to the operation of a machine or process. Only those who understand the implications in the controlling logic, and who understand the consequences of forced I/O on the machine or process, should attempt to use this function.

WARNING

UNINTENDED EQUIPMENT OPERATION

You must have prior knowledge of the process and the controlled equipment and the modified behavior in Control Expert before attempting to force I/O or numeric values to memory locations.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

NOTE: Before forcing outputs, understand that forced outputs (%M) exhibit different behavior with Modsoft/NxT/Concept than Control Expert.

With Modsoft/NxT/Concept you cannot force outputs when the Memory Protect switch of the Quantum CPU is set to the "On" position.

With Control Expert you can force outputs even when the Memory Protect switch of the Quantum CPU is set to the "On" position.
With Modsoft/NxT/Concept forced outputs maintain their values following a cold start.

With Control Expert forced outputs lose their disabled state following a cold start.

Preset Force Values in Offline Mode

The Modification Values and Force Values for variables can be preset in offline mode via animation tables. This information can be transferred to PLC later.

Presetting values can also be used for multiple modification and forcing of Boolean variables.

Preset Force Values in Project Information

The preset force values of variables are included in the

download (Transfer Project to PLC ) information of a project
upload (Transfer Project from PLC ) information of a project.

The Modification Value /Force Value attribute of a variable is part of the animation table information.

Include in Upload Information

In the properties dialog of an animation table you can activate/deactivate an additional property (Include in Upload Information).

As a default this property is activated.

This check box in the property dialog of an animation table is enabled only, if Animation tables is activated via Project Settings > General > PLC embedded data > Upload information.

Implementing Forcing Mode

This forcing mode is only available for variables responding to these conditions:

The variable is an EBool type.
The forcing attribute is validated in the variable editor.
The variable is a located variable.
The variable is an unlocated variable with the following restrictions:
- for Modicon M580 with a firmware version greater or equal to 2.10, the unlocated variable can be in an EDT or in a Device DDT,
- for Modicon Quantum 140 CPU 651 50, 140 CPU 651 60, 140 CPU 652 60,140 CPU 658 60, 140 CPU 670 60, 140 CPU 671 60, 140 CPU 672 60, 140 CPU 672 61, 140 CPU 678 61, with a firmware version greater or equal to 3.0 the unlocated variable can only be in a Device DDT (X80 modules in EIO drops).
- for Modicon M340 and for Momentum the unlocated variable can not be forced.
NOTE: Forcing/unforcing unlocated variables does not update %SW108.

Analog I/O variables forcing is managed in a different way:

On analog Device DDT, a set of sub fields (for example EIO2_d1_r0_s1_AMI0800.ANA_CH_IN[0].ANA.FORCE_CMD) allows to force analog I/Os with a predefined value.
For Modicon M580 and M340 PLCs the analog I/Os variables can be forced in the program.

NOTE: With the animation table, it is not possible to set or reset the bit associated to step S.x.

Forcing a Variable

To force a located Boolean variable, carry out the following actions:

Step	Action
1	Use the mouse to select the Boolean variable.
2	Press one of the buttons corresponding to the desired value, or from the contextual menu, execute the Force to 0 or Force to 1 commands. To force several variables simultaneously, see Forcing several located variables.

Step

Action

Use the mouse to select the Boolean variable.

Press one of the buttons corresponding to the desired value, or from the contextual menu, execute the Force to 0 or Force to 1 commands.

To force several variables simultaneously, see Forcing several located variables.

Unforcing a Variable

To unforce a located Boolean variable, carry out the following actions:

Step	Action
1	Use the mouse to select the Boolean variable.
2	Press the . button or execute the Unforce command from the contextual menu. To unforce several variables simultaneously, see Unforcing several located variables

Step

Action

Use the mouse to select the Boolean variable.

Press the . button or execute the Unforce command from the contextual menu.

To unforce several variables simultaneously, see Unforcing several located variables

When a variable is unforced, the letter F no longer appears in front of the value.

Creating an Offline Forcing Animation Table

To create a new animation table of forced bits from scratch, carry out the following actions:

Step	Action
1	Create a new (permanent) animation table via the Project Browser .
2	Enter the memory bits you want to force either as single bits (like %M1) or as a bit array (like M1:100).
3	Press the Force button.
4	Press the Swaps to multiple mode button.
5	Enter forcing values 0 or 1 in the Force value column.

To create a new animation table of existing forced bits in the PLC, carry out the following actions:

Step	Action
1	There are 3 ways to open the Forced bits animation table: In the status bar click the red F . In the Project Browser right-click Animations Tables and select Open Forced Bits Table from the context menu. Via Tools > PLC Screen open the PLCScreen dialog. In the Information tab under APPLICATION > MISCELLANEOUS click the FORCED BITS line.
2	Since this animation table is temporary only, copy and paste the animation table via context menu of the Project Browser.
3	Make the copied animation table permanent (using the Temporary table button ).
4	In the copied Forced bits animation table press the Force button.
5	Press the Swaps to multiple mode button.
6	Press the Populates multiple values using existing forced bits button. Result: The Force value column is populated.

Build/Build changes and Save your application.

By building, the values entered in the Force value column will be included in the upload information which is downloaded into the PLC.

Forcing by Use of an Offline Forcing Animation Table

To force values before starting the PLC, carry out the following actions:

Step	Action
1	Open an existing application (.STU, .STA or an uploaded application).
2	Connect to the PLC.
3	Open the manually created/copied Forced bits animation table (see Creating an Offline Forcing Animation Table).
4	Press the Force button to enter forcing mode.
5	Press the Swaps to multiple mode button.
6	Press the Execute multiple button to force the bits from the preset Force value column.
7	Now you can start your application.