# SimpleReadCoilInput ## `SimpleReadCoilInput` (FB) `FUNCTION_BLOCK` SimpleReadCoilInput ### Representation
### Evaluation of the actual values for function codes 01 (Read Coils) or 02 (Read Discrete Inputs) When evaluating the actual values, only the output `arxValue` must be considered. This is an array with 64 elements of type `BOOL` (1 - 64 Coils / Inputs). The specification of the bits to be transmitted is primarily determined by the choice of the function code (eFunctionCode), the start address (wStartAddr) and the desired number of Coils / Inputs (`wNumberOfCoils`) in the range 1 - 64. The actual values are available as follows: The first element `arxValue[0]` contains the state of the coil with the number `wStartAddress` The second element `arxValue[1]` contains the state of the coil with the number `wStartAddress` + 1 The third element `arxValue[2]` contains the state of the coil with the number `wStartAddress` + 2, etc. Unused elements of `arxValue` are described with FALSE. Task: Read the actual value of coil 17 Settings: eFunctionCode: ReadFunctionCodesCoilInput.FC01\_ReadCoils wStartAddr = 17 wNumberOfCoils = 1 `arxValue[0]`: Actual value of coil 17 `arxValue[1]`: FALSE `arxValue[2]`: FALSE … `arxValue[63]`: FALSE ### CODESYS InOut: | Scope | Name | Type | Initial | Comment | | ----------- | ------------------- | -------------------------------------- | -------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- | | Input | `xEn` | `BOOL` | TRUE | Enable / disable communication (TRUE = enable) | | Input | `byUnitId` | `BYTE` | 0 | Device address | | Input | `xUpdateActual` | `BOOL` | FALSE | Update of actual values (on every rising edge) | | Input | `xResError` | `BOOL` | FALSE |

Reinitialization of the outputs eErrorCodeCom or
eErrorCodeDev to the error-free state (on every
rising edge)

| | Inout | `ModbusClient` | `ModbusClientBase` | | Client of the device | | Output | `eFunctionCodeFb` | ReadFunctionCodesCoilsInputs | | Feedback - Modbus function code for the Modbus telegram | | Output | `wStartAddrFb` | `WORD` | | Feedback - Start address of the coils/inputs to be read | | Output | `wNumberOfCoilsFb` | `WORD` | | Feedback - Number of coils/inputs to be read (1 - 64) | | Output | `arxValue` | `ARRAY` \[0 .. 63] `OF` `BOOL` | | Array with the current coil/input states | | Output | `xAlarm` | `BOOL` | | Collective fault (TRUE = fault) | | Output | `xAlarmCom` | `BOOL` | | Collective fault - communication (TRUE = fault) | | Output | `eErrorCodeCom` | ModbusErrorCode | | Error code - communication (0 = no error) | | Output | `eErrorCodeDev` | SIMPLE\_READ\_COIL\_INPUT\_ERROR\_CODE | | Error code - device (0 = no error) | | Output | `xBusy` | `BOOL` | | Communication indicator (TRUE = communication) | | Input Const | `wNumberOfCoils` | `WORD` | 1 | Number of coils/inputs to be read (1 - 64) | | Input Const | `eFunctionCode` | ReadFunctionCodesCoilsInputs | ReadFunctionCodesCoilsInputs.FC01\_ReadCoils | Modbus function code for the Modbus telegram | | Input Const | `wStartAddr` | `WORD` | | Start address of the coils/inputs to be read | | Input Const | `tTimeUpdateActual` | `TIME` | TIME#3s0ms |

Update interval for the processes influenced by the input
xUpdateActual influenced

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