Hi Folks,
I'm starting work on an installation that will use network data from things like card access use, temperature, hvac settings, electricity usage, etc...

To get things started, I've been trying to get netsend and netreceive to work between 2 Macs. I'm using Network Utility to see what ports are in use, and although I'm able to send successfully using a few of them, I am unable to receive. So, a couple of questions...

Are netsend/receive the right objects for me to be using in the 1st place?

Should I be creating my own port somehow or looking for a specific port that's already being detected by my system?

I've tried turning Firewalls off on the computers, and also made sure that PD is allowed to communicate.

Thanks, Matt

@mattm Hello Matt.....
Try with these...... and if you still have problems then post your patch and we will test it for you......
try me.zip
You have to set the port for sending and receiving (the same..... it is the port that netsend and netreceive will be "talking" through)
Usually ports in the range 6000-9999 and above 70000 are free, but that could be different on OSX.
David.

Hello David,

Thanks you for sending the patches. I am now able to get things working locally and between 2 computers. I'm impressed with how little latency there is. I've just now modified my patch to send a message as TCP over port 9001 and that also works.

Can I ask, what are the deciding factors for using UDP vs TCP? My guess is that I'll want to use TCP so I can identify and parse the multiple streams of data.

-Matt

@mattm Hello again Matt.
TCP has message verification.... if a packet is not received it will be sent again before the next......... http://www.cyberciti.biz/faq/key-differences-between-tcp-and-udp-protocols/..... udp doesn't care if the message arrives, and as there is no "connection" you can set many receivers to listen. It depends how much data, and whether you care more about an individual message, or the time it arrives.
In the example I gave you udp is good because a lot of messages are being sent and if the last message (for example) does not arrive then the fader is only "1 step behind".......

You can parse the multiple streams of data over one send using the "param1" "param2" etc. (they are just headers, you can put any name you wish) that I put in that patch. I have found a brick wall limit of 64 ports for multiple use of netsend in a patch in Pd Extended....... probably you will not need so many.
David.

Hello David,

Thanks again. You've been really helpful.

Matt

@mattm Hi!
How did your installation work out? I'm attempting to do something similar, it downloads information from the internet that should then trigger stuff in Pd. I'm using processing/p5 with node, but, nothing really happens in Pd. Curious to know how you solved it!
/Anton