Status and control word
Status word
The status word (SW) is located in the input process image, and is transmitted from the module to the controller.
Bit | SW.15 | SW.14 | SW.13 | SW.12 | SW.11 | SW.10 | SW.9 | SW.8 |
|---|---|---|---|---|---|---|---|---|
Name | Acyclic operation, 4 bit counter increments with each successful save | - | Old Novram object restored | Novram initialized | Novram objects locked | |||
Bit | SW.7 | SW.6 | SW.5 | SW.4 | SW.3 | SW.2 | SW.1 | SW.0 |
|---|---|---|---|---|---|---|---|---|
Name | - | - | - | - | No data written | - | - | Cyclic operation with handshake, "Data written" |
The meaning of the status word is displayed in the TwinCAT System Manager in the "Comment" field of the "Variable" tab (see following figure).
Fig.26: Status word display in TwinCAT System ManagerIndex 0xF100:01 | Name | Meaning |
|---|---|---|
0x0001 | Data stored | Data was saved |
0x0008 | MASK_NO_DATA_WRITTEN | No data was saved (process data length is zero) |
0x0100 | Novram objects locked | The structure in 0x2F00 was locked against changes (see chapter Protect acyclic structure against changes) |
0x0200 | Novram initialized | NOVRAM was reinitialized at startup "Manufacturer configuration active (once after first boot process)" |
0x0400 | Old Novram object restored | NOVRAM was initialized at startup with values from a buffer (if the module was switched off during saving). |
Control word
The control word (CW) is located in the output process image, and is transmitted from the controller to the module.
Bit | CW.15 | CW.14 | CW.13 | CW.12 | CW.11 | CW.10 | CW.9 | CW.8 |
|---|---|---|---|---|---|---|---|---|
Name | - | - | - | - | - | - | - | - |
Bit | CW.7 | CW.6 | CW.5 | CW.4 | CW.3 | CW.2 | CW.1 | CW.0 |
|---|---|---|---|---|---|---|---|---|
Name | - | - | - | - | - | Unlock Novram objects | Lock Novram objects | Cyclic operation with handshake, "Start Writing" |
The meaning of the control word is displayed in the TwinCAT System Manager in the "Comment" field of the "Variable" tab (see following figure).
Fig.27: Control word display in TwinCAT System ManagerIndex 0xF200:01 | Name | Meaning |
|---|---|---|
0x0001 | Store data | Data are saved |
0x0002 | Lock Novram objects | The structure in 0x2F00 is protected against changes. |
0x0004 | Unlock Novram objects | The protection against changes of the structure in 0x2F00 is removed. |