Ethercat random jitter fix

With refClockSyncCycles="-1" the value of the ecat.0.pll_reset_cnt pin is continuously increasing, it never stops, it increases in a positive direction more and more, in a short time it was already at 20,000

with  refClockSyncCycles="1" the pin ecat.0.pll_reset_cn remain stable = 0

can you run ethercat master a few times consecutively while running with

refClockSyncCycles="-1"

and paste here the DC reference and the App time values?

at least 3~4 consecutive times please

do the same for 

refClockSyncCycles="1"

What parameters should I check?

the name the pin

Sorry, not a pin

it is the output to the terminal when you send this command
ethercat master
in a terminal window

it will list various things, I am interested in DC reference, and APP time, they are near the end

ethercat master command outputs
Master0
Phase: Operation
Active: yes
Slaves: 20
Ethernet devices:
Main: 00:e0:b4:68:34:0a (attached)
....
...
...
Distributed clocks:
Reference clock: Slave 0
DC reference time: 829391683702736097
Application time: 829391693979787340


the above is what I'd like to see, thank you
 

I have commit a small change to enable you to set drive 1 as the reference clock please update the code from 

github.com/grandixximo/linuxcnc-ethercat

and run with this xml 


and confirm that DC reference clock is slave 1 and not 0 by running

ethercat master

in a terminal, I expect

Reference clock: Slave 1

I don't understand how can attachment file.
This test, are without your last fix.
I have executed N°3 test for refClockSyncCycles="1" and refClockSyncCycles="-1"


1° power on with <master idx="0" appTimePeriod="1000000" refClockSyncCycles="1">

Master0
Phase: Operation
Active: yes
Slaves: 4
Ethernet devices:
Main: 68:ed:a4:79:15:bb (attached)
Link: UP
Tx frames: 105648
Tx bytes: 22401382
Rx frames: 105647
Rx bytes: 22401017
Tx errors: 0
Tx frame rate [1/s]: 1053 1050 752
Tx rate [KByte/s]: 360.7 359.5 216.8
Rx frame rate [1/s]: 1053 1050 752
Rx rate [KByte/s]: 360.7 359.5 216.8
Common:
Tx frames: 105648
Tx bytes: 22401382
Rx frames: 105647
Rx bytes: 22401017
Lost frames: 0
Tx frame rate [1/s]: 1053 1050 752
Tx rate [KByte/s]: 360.7 359.5 216.8
Rx frame rate [1/s]: 1053 1050 752
Rx rate [KByte/s]: 360.7 359.5 216.8
Loss rate [1/s]: 0 0 0
Frame loss [%]: 0.0 0.0 0.0
Distributed clocks:
Reference clock: Slave 0
DC reference time: 829434877492390059
Application time: 829434927369399203
2026-04-13 22:35:27.369399203


2° power on with <master idx="0" appTimePeriod="1000000" refClockSyncCycles="1">

Master0
Phase: Operation
Active: yes
Slaves: 4
Ethernet devices:
Main: 68:ed:a4:79:15:bb (attached)
Link: UP
Tx frames: 201920
Tx bytes: 55838998
Rx frames: 201919
Rx bytes: 55838617
Tx errors: 0
Tx frame rate [1/s]: 1055 732 844
Tx rate [KByte/s]: 376.3 246.9 277.6
Rx frame rate [1/s]: 1055 732 844
Rx rate [KByte/s]: 376.3 246.9 277.6
Common:
Tx frames: 201920
Tx bytes: 55838998
Rx frames: 201919
Rx bytes: 55838617
Lost frames: 0
Tx frame rate [1/s]: 1055 732 844
Tx rate [KByte/s]: 376.3 246.9 277.6
Rx frame rate [1/s]: 1055 732 844
Rx rate [KByte/s]: 376.3 246.9 277.6
Loss rate [1/s]: 0 -0 0
Frame loss [%]: 0.0 -0.0 0.0
Distributed clocks:
Reference clock: Slave 0
DC reference time: 829435021988989029
Application time: 829435029703007959
2026-04-13 22:37:09.703007959

3° power on with <master idx="0" appTimePeriod="1000000" refClockSyncCycles="1">

Master0
Phase: Operation
Active: yes
Slaves: 4
Ethernet devices:
Main: 68:ed:a4:79:15:bb (attached)
Link: UP
Tx frames: 335803
Tx bytes: 102363460
Rx frames: 335802
Rx bytes: 102363095
Tx errors: 0
Tx frame rate [1/s]: 1062 800 845
Tx rate [KByte/s]: 375.7 272.1 283.3
Rx frame rate [1/s]: 1062 800 845
Rx rate [KByte/s]: 375.7 272.1 283.3
Common:
Tx frames: 335803
Tx bytes: 102363460
Rx frames: 335802
Rx bytes: 102363095
Lost frames: 0
Tx frame rate [1/s]: 1062 800 845
Tx rate [KByte/s]: 375.7 272.1 283.3
Rx frame rate [1/s]: 1062 800 845
Rx rate [KByte/s]: 375.7 272.1 283.3
Loss rate [1/s]: 0 -0 0
Frame loss [%]: 0.0 -0.0 0.0
Distributed clocks:
Reference clock: Slave 0
DC reference time: 829435160651165030
Application time: 829435171294192841
2026-04-13 22:39:31.294192841

1° power on with <master idx="0" appTimePeriod="1000000" refClockSyncCycles="-1">


Master0
Phase: Operation
Active: yes
Slaves: 4
Ethernet devices:
Main: 68:ed:a4:79:15:bb (attached)
Link: UP
Tx frames: 394894
Tx bytes: 122081343
Rx frames: 394893
Rx bytes: 122080980
Tx errors: 0
Tx frame rate [1/s]: 1056 1001 811
Tx rate [KByte/s]: 345.4 327.0 265.2
Rx frame rate [1/s]: 1056 1001 811
Rx rate [KByte/s]: 345.4 327.0 265.2
Common:
Tx frames: 394894
Tx bytes: 122081343
Rx frames: 394893
Rx bytes: 122080980
Lost frames: 0
Tx frame rate [1/s]: 1056 1001 811
Tx rate [KByte/s]: 345.4 327.0 265.2
Rx frame rate [1/s]: 1056 1001 811
Rx rate [KByte/s]: 345.4 327.0 265.2
Loss rate [1/s]: 0 -0 0
Frame loss [%]: 0.0 -0.0 0.0
Distributed clocks:
Reference clock: Slave 0
DC reference time: 829435219977025031
Application time: 829435246614056284
2026-04-13 22:40:46.614056284

2° power on with <master idx="0" appTimePeriod="1000000" refClockSyncCycles="-1">

Master0
Phase: Operation
Active: yes
Slaves: 4
Ethernet devices:
Main: 68:ed:a4:79:15:bb (attached)
Link: UP
Tx frames: 466209
Tx bytes: 145310656
Rx frames: 466208
Rx bytes: 145310307
Tx errors: 0
Tx frame rate [1/s]: 1055 865 766
Tx rate [KByte/s]: 345.2 278.2 243.7
Rx frame rate [1/s]: 1056 865 766
Rx rate [KByte/s]: 345.5 278.2 243.7
Common:
Tx frames: 466209
Tx bytes: 145310656
Rx frames: 466208
Rx bytes: 145310307
Lost frames: 0
Tx frame rate [1/s]: 1055 865 766
Tx rate [KByte/s]: 345.2 278.2 243.7
Rx frame rate [1/s]: 1056 865 766
Rx rate [KByte/s]: 345.5 278.2 243.7
Loss rate [1/s]: -1 -0 0
Frame loss [%]: -0.1 -0.0 0.0
Distributed clocks:
Reference clock: Slave 0
DC reference time: 829435319890377036
Application time: 829435334302407866
2026-04-13 22:42:14.302407866

3° power on with <master idx="0" appTimePeriod="1000000" refClockSyncCycles="-1">

aster0
Phase: Operation
Active: yes
Slaves: 4
Ethernet devices:
Main: 68:ed:a4:79:15:bb (attached)
Link: UP
Tx frames: 555839
Tx bytes: 174885365
Rx frames: 555839
Rx bytes: 174885365
Tx errors: 0
Tx frame rate [1/s]: 1054 901 812
Tx rate [KByte/s]: 345.2 292.8 259.7
Rx frame rate [1/s]: 1054 901 812
Rx rate [KByte/s]: 345.2 292.8 259.7
Common:
Tx frames: 555839
Tx bytes: 174885365
Rx frames: 555839
Rx bytes: 174885365
Lost frames: 0
Tx frame rate [1/s]: 1054 901 812
Tx rate [KByte/s]: 345.2 292.8 259.7
Rx frame rate [1/s]: 1054 901 812
Rx rate [KByte/s]: 345.2 292.8 259.7
Loss rate [1/s]: 0 -0 0
Frame loss [%]: 0.0 -0.0 0.0
Distributed clocks:
Reference clock: Slave 0
DC reference time: 829435419653140029
Application time: 829435435462157958
2026-04-13 22:43:55.462157958

Because dcRefClock="true" only for drive 1 and not for all drive ?

Yes, the reference is only one, and right now is 0, and that I/O might not be doing DC properly.
So I'm try to move it to the servo.

The ethercat master, I'm only interested in two values 

DC reference time: 
Application time:

And three times on the same run, not one time per run. Sorry about not being clear about it. Appreciate it if you could test it, thank you.

Manda il comando tre volte dopo aver iniziato, non una volta per avvio.

1° without power on <master idx="0" appTimePeriod="1000000" refClockSyncCycles="1">

DC reference time: 829435419653140029
Application time: 829439464192168202

2° without power on <master idx="0" appTimePeriod="1000000" refClockSyncCycles="1">

DC reference time: 829435419653140029
Application time: 829439529368163181

3° without power on <master idx="0" appTimePeriod="1000000" refClockSyncCycles="1">

DC reference time: 829435419653140029
Application time: 829439568792164528

4° without power on <master idx="0" appTimePeriod="1000000" refClockSyncCycles="1">

DC reference time: 829435419653140029
Application time: 829439599360167607


1° without power on <master idx="0" appTimePeriod="1000000" refClockSyncCycles="-1">

DC reference time: 829439756498240034
Application time: 829439771336260988

2° without power on <master idx="0" appTimePeriod="1000000" refClockSyncCycles="-1">
DC reference time: 829439756498240034
Application time: 829439799640262918

3° without power on <master idx="0" appTimePeriod="1000000" refClockSyncCycles="-1">
DC reference time: 829439756498240034
Application time: 829439828648257947

4° without power on <master idx="0" appTimePeriod="1000000" refClockSyncCycles="-1">
DC reference time: 829439756498240034
Application time: 829439854792266116

A question.
So is it better to work with refClockSyncCycles="1" or with
refClockSyncCycles="-1" and syncToRefClock="false"?
If the two settings are equivalent, does the value of refClockSyncCycles have to be 1 or can it take on values ​​other than 1, and how do I know what the correct value is in this case?