LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Intended usage of messenger channel ack

I am wondering what the intended usage of wiring true to wait for ack (F) in Write.VI of Messenger Channel is.
The reference of Write states:

wait for ack specifies whether this endpoint waits until a reader endpoint acknowledges receiving the message before writing the next element. The default is FALSE.

The reference of Read states:
ack id specifies the ID number of a message to be acknowledged. This input allows the endpoint to acknowledge receiving the previous message. Use this input as an alternative to the Write Ack endpoint to enable acknowledgement in the channel. You can use Write Ack on every iteration after reading a message, or you can use this input so that the reader endpoint both acknowledges the previous message and reads the next message. The default is 0.

 

I would think that the ack mechanism would work internally and that I don't have to hand an id to Read.VI, since Write.VI never returns and that it is why I have no knowledge about the just sent id. Furthermore there is no input in Write.VI to specify an id.

Channel Messenger Ack.png

 

Actor Framework
0 Kudos
Message 1 of 3
(226 Views)

Hi

 

This Power Point Presentation from 2016 goes a little more into depth :

 

https://www.argentaconsult.com/_userfiles/pages/files/mattspresentation.pptx

 

Regards

 

Message 2 of 3
(193 Views)

Thanks for sharing. So there is a mysterious magical message object in the presentation, which has a ackID property to read. But I think this message object didn't make it to LV2023, at least I have no knowledge about it.

Quiztus2_0-1723452676790.png

 

Actor Framework
0 Kudos
Message 3 of 3
(186 Views)