SimpleReadArray

SimpleReadArray (FB)

FUNCTION_BLOCK SimpleReadArray

Triggering of the transmission of Modbus data

The data transmission is triggered if at least one of the conditions described below is met:

Prerequisite: A suitable array is connected at the 'InputArray' input. This is indicated by the output 'xInputArrayValid' (= TRUE).

1. after an edge change at the 'xUpdateActual' input ( FALSE >> TRUE ) ( one-time )

2. after the expiration of the duration 'tTimeUpdateActual' ( 'tTimeUpdateActual' > 0 ) ( cyclic )

3. after a change of the array at the 'InputArray' input ( data type, size ) ( one-time )

4. after a change of essential parameters ( 'byUnitId', 'wRegisterAddr', 'eFunctionCode' ) ( one-time )

5. after an edge change on the input 'xEn' ( FALSE >> TRUE ) ( one-time )

6. after every cold start ( one-time )

After completion of the data transfer, the result is signalled ( 'xDataValid' = TRUE / FALSE ) and the transmitted data are stored in the 'InputArray' array.

Note: As of 07.07.2023 the data type of the array at the 'InputArray' input cannot be detected and evaluated ( CDS-43675 Compiler, AnyType: Extension for Arrays needed ). The tooltip help for the 'InputArray' input shows the possible array data types depending on the chosen function code.

InOut:

Scope	Name	Type	Initial	Comment
Input	xEn	BOOL	TRUE	Enable / disable communication ( TRUE = enabled )
Input	byUnitId	BYTE	0	Modbus address of the device
Input	InputArray	__SYSTEM.AnyType		Input for the array ( FC01/02: ARRAY OF BOOL, ARRAY OF BYTE ) ( FC03/04: ARRAY OF INT, ARRAY OF UINT, ARRAY OF WORD )
Input	xUpdateActual	BOOL	FALSE	Update of actual values (on every rising edge )
Input	xResError	BOOL	FALSE	Reinitialization of the outputs ‘eErrorCodeCom’ and ‘eErrorCodeDev’ to the error-free state (on every rising edge)
Inout	ModbusClient	ModbusClientBase		Client of the device
Output	eFunctionCodeFb	ReadFunctionCodes	ReadFunctionCodes.FC01_ReadCoils	Feedback - Modbus function code for the Modbus telegram
Output	wRegisterAddrFb	WORD	0	Feedback - start address of the register for the Modbus telegram
Output	diInputArrayNumb	DINT	0	Number of array elements at the 'InputArray' input depending on the Modbus function code
Output	xInputArrayValid	BOOL	FALSE	Validity of the array at the 'InputArray' input ( data type, size ) ( FALSE = not valid, TRUE = valid )
Output	xDataValid	BOOL	FALSE	Validity of the data in the 'InputArray' array ( FALSE = not valid, TRUE = valid )
Output	xAlarm	BOOL	FALSE	General fault ( TRUE = fault )
Output	xAlarmCom	BOOL	FALSE	General fault - communication ( TRUE = fault )
Output	eErrorCodeCom	ModbusErrorCode	ModbusErrorCode.NO_ERROR	Error code - communication ( 0 = no error )
Output	eErrorCodeDev	SIMPLE_READ_ARRAY_ERROR_CODE	SIMPLE_READ_ARRAY_ERROR_CODE.NO_ERROR	Error code - device (0 = no error)
Output	xBusy	BOOL	FALSE	Communication indicator ( TRUE = communication )
Input Const	eFunctionCode	ReadFunctionCodes	ReadFunctionCodes.FC03_ReadHoldingRegisters	Modbus function code for the Modbus telegram
Input Const	wRegisterAddr	WORD		Start address of the register for the Modbus telegram
Input Const	tTimeUpdateActual	TIME	TIME#3s0ms	Update interval for operations influenced by the input 'xUpdateActual'