RT Set time and EtherCAT

[fuchur]

Hi,

I have a NI 3110 Industrial Controller which controls several NI 9144 EtherCAT slaves. Due to the inherit drift of the clock in the controller I need to adjust the absolute time periodocally from the Windows-part of the program. I do this successfully using the "RT Set time and date" VI from the Real-time palette. However, after having adjusted the time on the controller, the 9144 chassis report an error 2147137804 - "Master is no longer sync'd with the slave device acting as the reference clock". To get rid of this, the only solution I found so far is to toggle the Scan engine mode from active to configuration and back to active.

Since this is not a good solution to the problem I wanted to know if there is a better one?

Thanks for any help,

Christoph

[DirkW · Accepted solution]

Open the ni-rt.ini on your RT target and find the following section:

[TIME SYNC]
source.ethercat.enable = TRUE
source.ethercat.usable = TRUE
source.ethercat.masterID = 0
source_priority = ethercat;

Change the first line
source.ethercat.enable = FALSE

This will make the slaves no longer synchronize to the first slave. Instead, all the slaves synchronize to the master clock. See if it helps in this situation.

DirkW

[fuchur]

Hi,

thank you for the tip - I will try this as soon as possible. The master clock that you mention: is it the clock of the RT system on the Hypervisor?

Christoph

[DirkW]

yes the nanosecond realtime clock of  LV RT.

DirkW