The Function represents a shift register for any kind of Datatype (using variant).
It is possible to shift the elements in the array at bufferRegister to the left (index array[n]:=array[n+1]) or right (index array[n]:=array[n-1]).
It could be used for material tracking trough a machine or a process, e.g. for a rotary indexing table.
bufferRegister.| LGF_ShiftRegister (FB) | ||||||||
|---|---|---|---|---|---|---|---|---|
| Bool | enable | valid | Bool | |||||
| Bool | shiftLeft | busy | Bool | |||||
| Bool | shiftRight | error | Bool | |||||
| UInt | shiftRange | status | Word | |||||
| Bool | reset | leftShiftCount | DInt | |||||
| Bool | clear | rightShiftCount | DInt | |||||
| Bool | fill | shiftOffsetCounter | DInt | |||||
| Variant | initialItem | diagnostics | LGF_typeDiagnostics | |||||
| Variant | bufferRegister | Variant | ||||||
| Identifier | Data type | Default value | Description |
|---|---|---|---|
| enable | Bool | FALSE | TRUE: Enable functionality of FB |
| shiftLeft | Bool | FALSE | Rising edge: Elements in the array `bufferRegister` shifted left. Elements moved from index `N` to `N - 1`. The element at index `N = 0`is overwritten |
| shiftRight | Bool | FALSE | Rising edge: Elements in the array `bufferRegister` shifted right. Elements moved from index `N` to `N + 1`. The element at index `N = lastIndex` is overwritten |
| shiftRange | UInt | 1 | Number of places to be shifted in the `bufferRegister` input array |
| reset | Bool | FALSE | Initializing the buffer (reset the index and the counter) |
| clear | Bool | FALSE | Clear buffer elements in `bufferRegister` with `initalItem` |
| fill | Bool | FALSE | Overwrite buffer elements after shift operation. * `shiftLeft` - the most right element/s * `shiftRight` - the most left element/s overwritten by `initalItem`. |
| initialItem | Variant | --- | Value with which the ARRAY of the buffer is initialized (usually: `0` / default value) |
| Identifier | Data type | Description |
|---|---|---|
| valid | Bool | TRUE: Valid set of output values available at the FB |
| busy | Bool | TRUE: FB is active and new output values can be expected |
| error | Bool | FALSE: No error TRUE: An error occurred during the execution of the FB |
| status | Word | 16#0000-16#7FFF: Status of the FB 16#8000-16#FFFF: Error identification (see following Table) |
| leftShiftCount | DInt | Number of left shift operations since clearing |
| rightShiftCount | DInt | Number of right shift operations since clearing |
| shiftOffsetCounter | DInt | Offset of shift operations. `rightShift` - `leftShift` |
| diagnostics | LGF_typeDiagnostics | Diagnostic structure to store and transfer diagnostic information from blocks through the interface. |
| Identifier | Data type | Description |
|---|---|---|
| bufferRegister | Variant | Buffer / Register memory as ARRAY, which keeps the data. The data in the register is shifted left or right depending on the command. |
| Code / Value | Identifier / Description |
|---|---|
| 16#0000 | STATUS_NO_ERROR Status: Execution finished without errors |
| 16#7000 | STATUS_NO_CURRENT_JOBS Status: No current jobs, initial state |
| 16#7001 | STATUS_FIRST_CALL First call after incoming new job (rising edge 'enable') |
| 16#7002 | STATUS_SUBSEQUENT_CALL Status: Subsequent call during active processing without further details |
| 16#8001 | ERR_BUFFER_EMPTY Error: The buffer is empty |
| 16#8002 | ERR_BUFFER_FULL Error: The buffer is full |
| 16#8200 | ERR_NO_ARRAY Error: No array is present at the input `bufferRegister` |
| 16#8201 | ERR_CLEARING_WITHOUT_INITIAL_ITEM Error: Clearing `bufferRegister` without an `initialItem` is not possible. |
| 16#8202 | ERR_FILL_WITHOUT_INITIAL_ITEM Error: Option `fill` the buffer after shift operation without an `initialItem` is not possible. |
| 16#8203 | ERR_WRONG_TYPE_INITIAL_ITEM Error: The data type of the input `initialItem` does not correspond to the data type of the array at the InOut parameter `bufferRegister`. |
| 16#8204 | ERR_BOOL_NOT_SUPPORTED Error: Boolean variables and arrays are not supported by `MOVE_BLOCK_VARIANT`. (Use a PLC Datatype instead) |
| 16#8401 | ERR_MULTIPLE_COMMANDS_DEDECTED Error: More than one command present at the same time. Only one of the inputs `shiftLeft`, `shiftRight` or `clear` is allowed. |
| 16#8402 | ERR_IN_SHIFT_RANGE Error: The value at `shiftRange` must not exceed the maximum size of the Array at `bufferRegister`. |
| 16#8600 | ERR_UNDEFINED_STATE Error: Due to an undefined state in state machine |
| 16#8610 | ERR_CLEAR_BUFFER Error: While clearing buffer in block `MOVE_BLK_VARIANT``. Check `subFunctionStatus` code. |
| 16#8611 | ERR_SHIFT_BUFFER_LEFT Error: While shift buffer left in block `MOVE_BLK_VARIANT` - check `subFunctionStatus` code |
| 16#8612 | ERR_SHIFT_BUFFER_LEFT_FILL Error: While fill buffer after shift left in block `MOVE_BLK_VARIANT` - check `subFunctionStatus` code |
| 16#8621 | ERR_SHIFT_BUFFER_RIGHT Error: While shift buffer right in block `MOVE_BLK_VARIANT` - check `subFunctionStatus` code |
| 16#8622 | ERR_SHIFT_BUFFER_RIGHT_FILL Error: While fill buffer after shift right in block `MOVE_BLK_VARIANT` - check `subFunctionStatus` code |
Diagnostic structure to store and transfer diagnostic information from blocks through the interface.
| Identifier | Data type | Default value | Description |
|---|---|---|---|
| status | Word | 16#0000 | Status of the Block or error identification when error occurred |
| subfunctionStatus | Word | 16#0000 | Status or return value of called FB's, FC's and system blocks |
| stateNumber | DInt | 0 | State in the state machine of the block where the error occurred |
| Version & Date | Change description | |
|---|---|---|
| 1.0.0 | Siemens Industry Online Support | |
| 03.07.2018 | First released version | |
| 3.0.0 | Simatic Systems Support | |
| 09.04.2021 | Refactoring and alignment to Datatype Variant Insert documentation | |
| 4.0.0 | Simatic Systems Support | |
| 04.09.2024 | Rework to PLC Open `Enable` behavior Add `reset` input / counter outputs Fix Bug while filling after left shift operation Rework to diagnostic output datatype | |