NSD ABSOCODER NCW-3DNECMP Specifications & Instruction Manual page 77

APPENDIX 2-2. DC-Synchronous (SM2/Sync0)
DC-Synchronous (SM2/Sync0) is a synchronous mode with SYNC0 event. This mode does the OUTPUT/INPUT
data processing with synchronizing the SYNC0 event. For more detail, refer to the figure (Synchronous with
SM2/Sync0) below.
For NCW-3DNEC, following data is categorized in OUTPUT or INPUT.
- OUTPUT data: PRESET, error clear
- INPUT data: Position data, status input
SM2 event occurs when NCW-3DNEC receives the communication frame sent from the EtherCAT master.
Thus it includes the jitter by the EtherCAT master.
The SYNC0 event can occur by specifying the time in order to prevent affecting slaves from the jitter.
Also, slave devices can be synchronized with high accuracy less than 1μs by using the DC (Distributed Clocks)
function.
NOTE
The EtherCAT master with "Class A" is needed when using the DC-Synchronous function.
PLC/NC Task
O Calc
I
Communication
I
：INPUT
O
：OUTPUT
U
：User Shift(Slave)
●INPUT latch timing
The OUTPUT data processing cannot be executed if the EtherCAT system is in "Safe-operational" state.
Therefore, the processing timing of the following INPUT data moves forward.
SM2 Event
SYNC0 Event
Frame
Frame
U
1C32: 09
1C32: 06
OUTPUT Latch
OUTPUT Valid
Figure: Synchronous with SM2/Sync0
1C32: 02
1C32: 05
1C33: 09
1C33: 06
INPUT Valid
INPUT Latch
70
PLC/NC Task
SM2 Event
O Calc
I
Communication
Frame
Frame
: Output Mapping
: Output
: Input
: Input Mapping
SYNC0 Event
U