FB_PreventaDiag

Overview

Type:	Function block
Available as of:	V1.0.0.0
Inherits from:	-
Implements:	-

Functional Description

The FB_PreventaDiag function block decodes the bit sequence applied to its input i_xDiagSignal. This sequence is delivered from a Preventa XPS safety module via the auxiliary module output Z1. The pulsed message encodes diagnostic information on the module (see table in section Status Output at q_dwStatus for a list of defined codes).

In order to analyze the incoming sequence and deliver a diagnostic code, the function block needs to be activated by setting its i_xEnable input to TRUE. If the i_xEnable input is reset to FALSE, the sequence analysis is stopped and the function block outputs are set to their default values.

At the i_timTaskCycle input, the cycle time of the task in which the function block is called has to be specified. Using this time value, the function block evaluates whether the task is fast enough to correctly detect the bit sequence signal output by the Preventa XPS safety module. See chapter General Considerations for details.

NOTE: The function block must only be used in a cyclic task and it has to be executed in each task cycle.

The function block implements an internal routine which verifies that it is called in each task cycle. If not, the function block enters the error state (error code 16#1000).

The diagnostic data decoded from the incoming bit sequence is delivered as a STRUCT data type at q_stDiagCode. Depending on the analysis result, the corresponding structure element q_stDiagCodes is set to TRUE. The output q_dwStatus shows the 6-bit code part (without the 4-bit start part) of the last detected bit sequence as a double word.

After detecting a static TRUE signal at input i_xDiagSignal, the output q_xComWireInShort switches to TRUE, thus indicating a possible short circuit in the Preventa XPS safety module. A static FALSE signal at i_xDiagSignal results in switching q_xComWireOpen to TRUE.

The function block provides several outputs for the function block status (q_xBusy, q_xValid) as well as error indications (q_xError and q_wErrorId).

Interface

Input	Data type	Description
i_xEnable	BOOL	TRUE activates the function block. While activated, the bit sequence at input i_xDiagSignal is continuously read and evaluated.
i_xDiagSignal	BOOL	Input for connecting the bit sequence output by the Preventa XPS safety module. Connect this input to the variable which is assigned to the auxiliary output Z1 signal.
i_timTaskCycle	TIME	Currently configured cycle time in [ms] of the cyclic task in which the function block is executed. NOTE: To detect the bit sequence correctly, the task cycle time must be equal to or less than 50 ms. See chapter General Considerations for details.

Input

Data type

Description

i_xEnable

BOOL

TRUE activates the function block. While activated, the bit sequence at input i_xDiagSignal is continuously read and evaluated.

i_xDiagSignal

BOOL

Input for connecting the bit sequence output by the Preventa XPS safety module.

Connect this input to the variable which is assigned to the auxiliary output Z1 signal.

i_timTaskCycle

TIME

Currently configured cycle time in [ms] of the cyclic task in which the function block is executed.

NOTE: To detect the bit sequence correctly, the task cycle time must be equal to or less than 50 ms. See chapter General Considerations for details.

Output	Data type	Description
q_xBusy	BOOL	If this output is set to TRUE, the function block execution is in progress.
q_xError	BOOL	If this output is set to TRUE, the function block has detected an error. For details, refer to q_wErrorId.
q_wErrorId	WORD	Provides diagnostic and status information as a numeric value. Possible error codes are listed in section Error Codes.
q_xValid	BOOL	The output value TRUE indicates for one cycle a valid bit sequence at the i_xDiagSignal input.
q_stDiagCode	ST_DiagCode	Diagnostic information decoded from the input bit sequence: the corresponding bit values in the ST_DiagCodes structure are set to TRUE.
q_dwStatus	DWORD	Indicates the 6-bit code part (without the 4-bit start part) of the last detected bit sequence converted to a double word data type. Refer to the section below this table.
q_xComWireInShort	BOOL	The output value TRUE indicates a static TRUE signal at input i_xDiagSignal. This may indicate a short circuit in the Preventa XPS safety module or the wire from the auxiliary Z1 output to the controller input.
q_xComWireOpen	BOOL	The output value TRUE indicates a static FALSE signal input i_xDiagSignal. This may indicate that either the auxiliary output Z1 of the Preventa XPS safety module is not connected correctly to the controller input or the Preventa XPS safety module is switched off. Verify that the wiring and the power supply of the Preventa XPS safety module are correct and the auxiliary Z1 output is not overloaded.

Status Output at q_dwStatus

The sequence is composed of 10 bits with a duration of 200 ms each. The first 4 bits (always 0010) represent the start sequence followed by a 6-bit code sequence.

The following table lists the 6-bit code part of the diagnostic codes sent by the Preventa XPS safety module, as applied to the q_dwStatus output.

Code	Code part of bit sequence	Decimal value	Description	Class. ⁽¹⁾
40	101111	47	Device in operating state Run, safety-related outputs activated.	S
39	101110	46	Start input activated. Waiting for falling edge for monitored start.	S
38	101010	42	Waiting for rising edge for automatic/manual or monitored start.	S
37	101011	43	Waiting for start-up test.	S
36	101001	41	Input S63 is expected to change its state.	S
35	101000	40	Input S62 is expected to change its state. In the case of a configuration with antivalent inputs, the inputs S62 and S63 are expected to change their state.	S
34	111000	56	Input S53 is expected to change its state.	S
33	111001	57	Input S52 is expected to change its state. In the case of a configuration with antivalent inputs, the inputs S52 and S53 are expected to change their state.	S
32	111011	59	Input S43 is expected to change its state.	S
31	111010	58	Input S42 is expected to change its state. In the case of a configuration with antivalent inputs, the inputs S42 and S43 are expected to change their state.	S
30	111110	62	Input S33 is expected to change its state.	S
29	111111	63	Input S32 is expected to change its state. In the case of a configuration with antivalent inputs, the inputs S32 and S33 are expected to change their state.	S
28	111101	61	Input S23 is expected to change its state.	S
27	111100	60	Input S22 is expected to change its state. In the case of a configuration with antivalent inputs, the inputs S22 and S23 are expected to change their state.	S
26	110100	52	Input S13 is expected to change its state.	S
25	110101	53	Input S12 is expected to change its state. In the case of a configuration with antivalent inputs, the inputs S12 and S13 are expected to change their state.	S
24	110111	55	Safety-related inputs deactivated, safety-related outputs deactivated.	S
23	110110	54	Instantaneous safety-related outputs are deactivated, delayed safety-related outputs are still activated.	S
22	100111	39	Synchronization alert. Both synchronized safety-related inputs have been activated, but not within the synchronization time.	A
21	110011	51	Synchronization alert. One of the synchronized safety-related inputs is still deactivated, but the synchronization time has already elapsed.	A
20	100000	32	Antivalence alert at input S2x.	A
19	100110	38	Antivalence alert at input S1x.	A
18	100011	35	Cross-circuit detected at input used for Cancel Delay function.	E
17	110000	48	Cross-circuit detected at start input.	E
16	011100	28	Cross-circuit detected at input S63.	E
15	011101	29	Cross-circuit detected at input S62.	E
14	011111	31	Cross-circuit detected at input S53.	E
13	011110	30	Cross-circuit detected at input S52.	E
12	011010	26	Cross-circuit detected at input S43.	E
11	011011	27	Cross-circuit detected at input S42.	E
10	101100	44	Cross-circuit detected at input S33.	E
9	011000	24	Cross-circuit detected at input S32.	E
8	001110	14	Cross-circuit detected at input S23.	E
7	001111	15	Cross-circuit detected at input S22.	E
6	001101	13	Cross-circuit detected at input S13.	E
5	001100	12	Cross-circuit detected at input S12.	E
4	000111	7	Configuration error detected.	E
3	000110	6	General error detected in expansion module.	E
2	000011	3	General error detected.	E
1	101101	45	Supply voltage is out of tolerance.	E

(1) Classification of the message: A = alert, E = error, S = status

Error Codes

If the function block detects an error, the output q_xError switches to TRUE and an error code is indicated at q_wErrorId. This error ID provides detailed information on the error cause.

Error ID	Description
16#1000	Function block is not called cyclically. Remedy: Call the function block in a cyclic task and make sure that the function block call cannot be skipped (for example, by a preceding conditional jump).
16#1001	Invalid task cycle time connected to input i_timTaskCycle. Remedy: Connect a time value which is equal to or less than 50 ms. See chapter General Considerations for details.
16#1002	Synchronization with the bit sequence output by the Preventa XPS safety module not successful. (Error in state 20.) Remedy: Ensure that a valid signal (output at the auxiliary Z1 output of the Preventa XPS safety module) is connected correctly to the function block input and verify that the Preventa XPS safety module is in operating mode.
16#1004	The maximum number of invalid bit sequences is exceeded. (Error in state 30.) Remedy: Ensure that a valid signal (output at the auxiliary Z1 output of the Preventa XPS safety module) is connected correctly to the function block input and verify that the Preventa XPS safety module is in operating mode.
16#1005	Internal function block error. Remedy: Disable and then re-enable the function block.