Description

Function Description

This DFB can be used to save any errors in a diagnostics buffer.

The switching of input COND1 to 0 or the switching of input COND0 to 1 causes an error to be saved in the diagnostics buffer.

If both the COND1 and COND0 inputs are incorrect, one single error is saved. The error disappears when both the COND1 and COND0 inputs return to a correct value.

The additional parameters and can be configured.

NOTE: This diagnostic DFB cannot be used in a user DFB.

Representation in FBD

Representation:

Representation in LD

Representation:

Representation in IL

Representation:

CAL ALRM_1 (COND1:= Cond1_Input, COND0:= Cond0_Input, 
ERROR => Error_Output)

Representation in ST

Representation:

ALRM_1 (COND1:= Cond1_Input, COND0: = Cond0_Input, 
ERROR => Error_Output);

Description of the Parameters

The following table describes the input parameters:

Parameter	Type	Description
COND1	EBOOL	Input bit to be monitored in status 1. If the DFB is executed and this bit switches to 0, the DFB displays an error. If the input COND0 switches to 1, there is no new error. The default value is 1.
COND0	EBOOL	Input bit to be monitored in status 0. If the DFB is executed and this bit switches to 1, the DFB displays an error. If the input COND1 switches to 0, there is no new error. The default value is 0.

The following table describes the output parameters:

Parameter	Type	Description
ERROR	EBOOL	Error bit. This bit is set to 1 when an error appears. This bit is set to 0 if there is no longer an error.

Description of Variables

The following table describes the public variables:

Name	Type	Description
AREA_NR	INT	Area of automation system to be monitored. This word is used to specify which area of the automation system is to be monitored by the diagnostics DFB. Examples: Machining: No. 1 Milling: No. 2 Tapering: No. 3 AREA_NR must have the value 1, 2 or 3 in order for the user to identify the part of the automation system which is faulty. You are advised to make the above breakdown correspond to the functional module breakdown. AREA_NR can have a value between 0 and 15. The default value is 0.
OP_CTRL	EBOOL	Acknowledgement request. This bit indicates whether or not the operator needs to acknowledge the DFB instance: OP_CTRL = 0: the user does not have to provide acknowledgement, OP_CTRL = 1: the user has to provide acknowledgement. The default value is 0.