Allowed range for Slave Trigger Delay

[olifri]

Hallo,

I want to compensate the offset of the timestamp counters of four 5112 cards by apllying a value to the SlaveTriggerDelay property of each slave card. Doing this,I'm encountering Error(-1074135024)"Invalid value for parameter or attribute NISCOPE_ATTR_SLAVE_TRIGGER_DELAY".

1) My idea of this attribute is, that I can offset my timestamp counter on the card forward or backward, depending on the sign. Is this correct?
2) What's the range of this property, the values that I try to apply to are between 0.06s and 0.19s. That's the time that has been elapsed between two counter resets on different cards.

Thank you for your help

Oliver Friedrich

[Josh H]

Hi Oliver,

The Slave Trigger Delay property of NI-SCOPE is used to adjust the initial X value of the slave digitizers to correct for the propagation delay between the master trigger output and slave trigger input. The master will always trigger before the slaves, so this value will always be positive in a one master, several slaves synchronization scheme. So to answer your questions:

1) You can only correct for the slave triggering after the master. Any other type of correction could be done in software after you fetch the data.

2) The legal values for the property are from 0 and 0.00214 in seconds.

Please let me know if you have further questions.
Josh

[olifri]

Hallo Josh,

thanks for the quick and precise answer.

My approach is a little different than the "Synchronisation" example shipped with the 5112. I don't want to have the slaves triggered by the master all the time. I use this feature only once during a special synchronization procedure within my app to get the offsets of the timestamp counters. After this, all my cards trigger independly on their inputs but I can correlate the records by their timestamps.
I wanted to compensate the timestamp offset by applying to the SlaveTriggerDelay feature so I don't have to correct each record by software, but the range of the property is to small. I can reset four 5112 devices within ca. 20ms if the VIs are directly chained. But this 20ms I can't compensate anymore. But that's no big problem I can compensate for them within software, it's just less comfortable.
There are a couple of serious problems, take a look at my other posts in this forum.

Oliver