BECKHOFF EtherCAT Technology Section I - Manual (Page 82)

Distributed Clocks
I-62 Slave Controller – Technology
The registers used for SyncSignal Generation are shown in Table 33.
Table 33: Registers for SyncSignal Generation
Register Address Name Description
0x0141[3:2] ESC Configuration Enable/Disable DC Units (power saving)
0x0151 Sync/Latch PDI Configuration Configuration of SYNC/LATCH[1:0] pins
0x0980[0] Cyclic Unit Control Assignment of cyclic function to EtherCAT or
PDI
0x0981 Activation Activation of cyclic function and SYNC pins
0x0982:0x0983 Pulse Length of SYNC signals Length of SYNC impulse length
0x0984 Activation Status Activation status of SYNC0/SYNC1
0x098E SYNC0 Status Status of SYNC0 signal
0x098F SYNC1 Status Status of SYNC1 signal
0x0990:0y0997 SYNC0 Start Time Start System time of cyclic operation
0x0998:0x099F NEXT SYNC1 Pulse System Time of next Sync1 Pulse
0x09A0:0x09A3 SYNC0 Cycle Time Cycle Time of SYNC0
0x09A4:0x09A7 SYNC1 Cycle Time Cycle Time of SYNC1
NOTE: Some of these registers are set via SII EEPROM/IP Core configuration, or they are not available in
specific ESCs. Refer to Section II for details.
9.2.3.1 Cyclic Generation
In Cyclic Generation mode, the Sync unit generates isochronous SyncSignals after the Start Time.
The generation ends if the Cyclic Unit is deactivated or SYNC0/1 generation is deactivated. The Cycle
times are determined by the SYNC0/1 Cycle Time registers. The Pulse Length of the SYNC signals
has to be greater than 0. If the Pulse Length is greater than the Cycle Time, the SyncSignal will
always be activated after the Start Time.
9.2.3.2 Single Shot Mode
In Single Shot mode (SYNC0 Cycle Time set to 0), only one SyncSignal pulse is generated after the
Start Time is reached. Another pulse can only be generated by deactivating the Cyclic Unit
(0x0981[0]=0), reprogramming the Start Time, and reactivation of the Cyclic Unit.
9.2.3.3 Cyclic Acknowledge Mode
The Cyclic Acknowledge mode is typically used for generation of isochronous interrupts. The
acknowledged modes are selected by setting the Pulse Length of SYNC Signals to 0
(0x0982:0x0983). Each SyncSignal pulse remains active until it is acknowledged
– typically by a
µController – by reading the appropriate SYNC0 or SYNC1 Status register (0x098E, 0x098F). The first
pulse is generated after the Start Time is reached, following pulses are generated when the next
regular SYNC0/1 event would occur.
9.2.3.4 Single Shot Acknowledge Mode
In Single Shot Acknowledge mode (both Pulse Length of SYNC Signals and SYNC0 Cycle Time are
0), only one pulse is generated when the Start Time is reached. The pulse remains active until it is
acknowledged by reading the appropriate SYNC0/1 Status registers. Another pulse can only be
generated by deactivating the Cyclic Unit (0x0981[0]=0), reprogramming the Start Time, and
reactivation of the Cyclic Unit.