31st May 2011, 11:08 PM
Automated Home Guru
What affects DFP response / does beefer PC speed it up?
Was wondering if anyone knew if there's any affect on response on DFP with regards to the PC which Cortex is running (or if it might just be limited by Idratek's bus speed or something else)?
At the moment I've got it on an old 2GHz Intel Pentium M. I like the idea of lower power CPUs (possibly even Atom fit PC2) but am wondering about putting a Core2Duo behind it to see if the response on DFP screen redraws and User Defined Menus can be improved.
Any insight appreciated.
1st June 2011, 04:36 PM
Automated Home Guru
Packets to a DFP LCD screen have the lowest priority in Cortex.
When Cortex receives a packet (button, temperature, switch etc) it decides some response (if required) and prepares to send a packet. Some responses may cause an LED to turn on, Screen brightness to change, Relay to switch on, speak and Display messages.
So an incoming response may generate many outgoing packets.
Cortex does not send them out in the order they were generated. Each packet is assigned a priority. All the packets with priority 1 are sent, then priority 2 etc. It may be whilst sending packets with priority 5 say, new packets are required to be sent with priority 1 due to a new incoming packet, in which case priority 1 packets are again sent leaving display packets with priority 10 still waiting to be sent. Eventually all get sent.
The rational being that packets for say switching on a light are more important to give the user an expect quick response. Display packets being less important. It should be expect that packets can be sent at a rate of approx 11 or 12 per second bearing in mind each sent packet could illicit two acknowledge packets and possibly a third returned information packet increasing the network traffic considerably.
Having a fast processor helps in any latency between packets but not the transmission rate.
Bottom line is having a fast processor does help in the overal Cortex experience.
Note: A Macro ensures the packets it may cause to be sent are done in order.