Performing a Pulse Test on a Digital Output Module

Use the Tag Editor to create a tag at controller scope with a MESSAGE data type.

Go to the Ladder Editor, and insert a rung that contains an MSG instruction.

The instruction operand should be the MESSAGE tag you just created.

Select the button to the right of the operand to go to the

Message Configuration

dialog box.

For

Message Type

, choose Generic CIP.

For

Service Code

, enter 4C (Pulse Test service code).

For

Object Type

, enter 1E (Discrete Output Group).

For

Object ID

, enter 1.

Leave

Object Attribute

blank.

For

Source

, enter or choose a controller-scoped tag that is an INT[5].

If the tag does not exist yet, select the

Create Tags

button to create it.

For

Num. of Elements

, enter 10.

Leave the

Destination

blank.

Select the

Communication

tab.

For

Path

, enter module name or CIP path to the module.

For

Communication Method,

choose CIP.

Select

OK

.

Write logic or use the Data Monitor to set the values of the source tag elements:

To test the results of the pulse test, write logic to examine the EXERR member of the message tag when its DN bit is set and its ERR bit is not (meaning the message completed successfully).

Each bit in the EXERR member corresponds to an output point on the module. If the bit you performed the pulse test on is set to 1, the pulse test failed.