Configuring Timer DQ operating mode

Timer DQ

Timer DQ operating mode allows you to output up to two edges per application cycle (for example OB 91, OB 6x) at a specific time, for example, for use as a cam output.

Select the Timer DQ operating mode for the required channel.

图片: Mode of operation: Timer DQ

Inversion

You can invert the 24 V ** to adjust it to your process. By default, the ** is not inverted.

High-speed output

If you select the high-speed output option, the digital output is switched alternately to 24 V DC and ground.

Advantages of the high-speed output:

Extremely steep edges (output delay in the 1 μs range)

Extremely high switching frequencies

Maximum switching precision, for example, for use as a cam output

Assigning the output cam technology object

The output cam technology object must always be assigned to another technology object whose position is evaluated.

You can assign the output cam technology object to the following technology objects:

Synchronous axis

Positioning axis

External encoder

You can assign exactly one axis or one external encoder to the output cam.

You can assign multiple output cams to one axis or one external encoder.

Configuring the output cam technology object

Select the configuration of the output cam in the Technology objects folder in the project tree.

Configure the basic properties of the technology object in the Basic parameters configuration window.

图片: Basic parameters

Name

Define the name of the output cam in this field. The technology object is listed under this name in the project tree. The tags of the output cam can be used in the user program under this name.

Assigned axis or external encoder

STEP 7 displays the axis or external encoder assigned to the output cam. You can use the link to directly access the basic parameters of the higher-level technology object.

Output cam type

Select an output cam type on the basis of the required switching behavior:

Position-based cam (position-dependent switch-on/switch-off)

Time-based cam (position-dependent switch-on and position-independent or time-dependent switch-off)

Output cam reference

In this selection, configure whether the switching points of the output cams are to reference the actual position or the position setpoint.

Unit of measurement

The unit of measurement shown for the position of the output cam corresponds to the unit of measurement of the higher-level technology object.

When a time-based cam is selected as the output cam type, the unit of measurement for the switch-on duration and other times is also indicated. The unit of measurement for output cams is always ms.

Hardware interface

Select the type of cam output in the Hardware interface configuration window.

图片: Hardware interface

Select whether you want to output the switching **s generated at the digital output.

Activate output

Select one of the following two output options for outputting the cam track:

- Output via Timer DQ

For output by Timer DQ, select a cam output in the Output field. The selection box displays all channels that have been configured correctly.

- Output by digital output module

For output by a digital output module, select a digital output in the Output field. Only the digital outputs with previously defined PLC tags are displayed for selection.

Output deactivated
When output is deactivated, the cam track is evaluated only in the software.

Extended parameters > Activation time

图片: Activation time

The specified output cam type is indicated at the top of the Activation time configuration window.

For a time shift of the switch-on and switch-off times of the output cams, enter an activation time and a deactivation time.

Extended parameters Parameter > Hysteresis

图片: Hysteresis

To prevent unwanted changes in the switching state of the output cams of a cam track, enter a hysteresis value.

When using output cams that reference the actual position, it is advisable to enter a hysteresis value (> 0.0).

Cam track technology object

In addition to the output cam technology object already described, the cam track technology object is also available.