Process data
EtherCAT process data PDO (process data objects)
The EL32xx-xxxx provide a default process image consisting of
- per channel
- Status: 16 bit
Content: see chapter Status word - Value: 16 bit measured value
Presentation: see chapter "PDO presentation" - Device information (real-time, i.e. updated cyclically)
See also chapter “General Commissioning Instructions for an EtherCAT Slave” - WcState: 1 bit
TRUE: terminal has not transferred any valid values to EtherCAT in this cycle, measured values of the terminal may not be used.
Cause: either the terminal itself or another device in the same SyncUnit is not participating in the EtherCAT data exchange, rectify fault. - InputToggle: 1 bit
Bit change indicates new process data - Device information (non-realtime)
- State: EtherCAT state of the device INIT – PreOP – SafeOP – OP, BOOTSTRAP
- ADS address in the AMS Net ID system: for read/write access from the controller
Taking the example here of the EL3202, rev. 0022 (version 2022):
It is strongly recommended that the channel and device diagnostics be evaluated on the application side so that measured values do not continue to be not processed incorrectly, although the RTD terminal has already declared that it is incapable of measurement.
SyncManager
SM3, PDO assignment 0x1C13, for 0 ≤ n ≤ 7 (ch. 1 - 8) (depending on number of channels) | ||||
|---|---|---|---|---|
Index | Index of excluded PDOs | Size (byte.bit) | Name | PDO content |
0x1A0n (default) | - | 4.0 | RTD Inputs Channel | Index 0x60n00:01 - Underrange |
*) not for EL3214, EL3208 and EL3218
Process data preselection (predefined PDOs)
Since the EL32xx only have the standard process image, there are no selectable Predefined PDO:
Compact process image
Function available from EL3204 FW10
To save process data width, the 16-bit status can be excluded from transmission. Since no diagnostic information can be evaluated after this, this operation is not recommended.
EL3204 example: in the TwinCAT EtherCAT configuration, select the PDO objects 0x1A04 ... 0x1A07 (A) in the PDO assignment 0x1C13 (B) instead of the standard PDO 0x1A00...0x1A03.
