O

octal

An integer value displayed and entered in base 8 (that is, each digit represents 3 bits) and prefixed with 8#. Padded out to length of the BOOL or integer (1, 8, 16, or 32 bits). Every group of 3 digits is separated by an underscore for legibility when displayed.

ODVA

ODVA is an organization that manages the technical specifications and technical standards for the Common Industrial Protocol (CIP), the CIP Network adaptations of CIP — DeviceNet™, EtherNet/IP™, CompoNet™, and ControlNet™, along with CIP Safety™, the extensions to CIP for functional safety on CIP.

offline

A state in which a device is not in direct communication (for example, when programming in

Logix Designer

).

offset

The steady-state deviation of a controlled variable from a fixed set point. In a linear function (y=mx+b), the parameter (b) is used to drive the dependent variable (y) to zero when the independent variable (x) is zero.

one-shot

A programming technique that sets a bit for only one program scan.

online

A state in which a device is in direct communication (for example, when

Logix Designer

is monitoring the program file in a controller).

online data change

Using a peripheral device to change various data table values in a programmable controller while the logic program is running.

online editing

Making changes to a logic program in a programmable controller while the program is running.

operand

The specification of the source or destination referenced (used by) an instruction in a user program. The operand can be:

orientation

Robotic term for directional attitude or rotation about a point in Cartesian (3D) space. Orientation is expressed as three ordered rotations around the X, Y and Z Cartesian axes.

In the MCT and MCTP transformation motion instructions, the MCT's and MCTP's Orientation operand specifying the Rotation Vector for Kinematics transformations changed from previous releases to apply Rotation ordering first about X, then Y, then Z. (The prior Rotation ordering was first about Z, then Y, then X.) This change impacts the Initial position of any MCT or MCTP using 2Dimension, 2D, or 3D Rotation vector. A 1D Rotation is not affected.

orphan

Many components in the

Logix Designer

programming environment are actually composed of several pieces. For instance, a tag is composed of the tag object you see, plus an underlying data target. This target can be either a data table object, or a Message, Axis, or Motion Group object. Under certain fault conditions (for example, a loss of communications while creating or deleting one of these composite objects), the pieces can get separated. For instance, the tag may get deleted, but the underlying target object may not. In this case, the lone target object is considered an "orphan" component in the system. In other cases, the tag may be created, but the underlying object may not. This leaves a tag that you can see, but that is not really all there. This is considered an orphan tag.

These orphans can exist in the Controller, in the project file, or both. Uploading from a controller that contains orphan components saves them to the project file. These components are undesirable, and can cause problems, particularly tag, Message, Axis, and Motion Group orphans. For this reason, a project that contains these orphans will not download.

On Download, a message in the Results window will indicate the presence of orphan components, and direct you to use the Compact command from the File menu, or to use Export and Import to purge these orphans from the project. Once removed from the project, downloading to the controller will eliminate them from the controller.

Orphan data table objects are much more benign, and much more difficult to detect. The current release does not detect data table orphans on download, and the Compact command will not remove them; Export and Import, however, will.

output bias

An axis parameter that is summed with command output from the control loops. This offset can be used to compensate for a bias load on the motor, such as from an axis that is fighting against gravity.

output cam element

One element of an output cam specifically defined by its Output Bit, Latch Type, Unlatch Type, Left Position, Right Position, Duration, Enable Type, and Enable Bit.

output device

A device, such as a pilot light or motor starter coil, that receives data from the controller.

output limit

An axis parameter that limits the analog output command that can be sent to the drive. This is a physical limit to protect the drive amplifier from providing too much current to the motor.

output offset

Refers to compensation. It is used to correct the problem drift in a servo drive by adding a fixed value, called output offset, to the servo output. This value is chosen to achieve near zero drive velocity when the uncompensated servo output value is zero.

output parameter

Data that is produced as a direct result of executing an instruction or function.

overtravel

The limit that describes the maximum distance the hardware allows an axis to travel in a certain direction.

owner module

The controller that creates the primary configuration and communication connection to a module.

ownership

The ownership hierarchy has two levels:

When a sequence or phase is attached to a program and ownership is overridden by Logix Designer, Logix Designer can command the sequence or phase. The program is still attached, but cannot command until the override has been released.