SimpleReadArray

SimpleReadArray (FB)

FUNCTION_BLOCK SimpleReadArray

Triggering 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 to the input 'InputArray'. This is indicated by the output 'xInputArrayValid' (= TRUE).

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

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

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

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

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

6. after every cold start (one-time)

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

Note: As of 07.07.2023 the data type of the array at the input 'InputArray' cannot be detected and evaluated (CDS-43675 Compiler, AnyType: Extension for Arrays needed). The tooltip help for the input 'InputArray' 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 = enable)
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	Reinitialize the outputs 'eErrorCodeCom' and 'eErrorCodeDev' to the fault-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 input 'InputArray' in dependence on the Modbus function code
Output	xInputArrayValid	BOOL	FALSE	Validity of the array at the input 'InputArray' (data type, size) (FALSE = not valid, TRUE = valid)
Output	xDataValid	BOOL	FALSE	Validity of the data in the array 'InputArray' (FALSE = not valid, TRUE = valid)
Output	xAlarm	BOOL	FALSE	Collective fault (TRUE = fault)
Output	xAlarmCom	BOOL	FALSE	Collective 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 the operations influenced by the input ‘xUpdateActual’