|ZigBee Wireless Data Links|
|Remote Station Scan Rates|
When a station is attached to a remote, the comms time of messages takes significantly longer than a direct wired connection, thus on MicroScan page settings, a restriction is placed on pages with remote connections to be scanned at the Medium Scan Rate (15 seconds) as shown below:
Comms Update Speeds
One data message round trip approx 400mSec.
To read all 16 direct inputs on an A16, 2 seconds.
To read Digital input states, counters 1 second
To read 4 expanders 2 seconds.
To read ambient temp sensor 1/2 second.
To read ALL data from an A16 would require 2+1+2+1/2 = approx 6 seconds.
Comms Station Timeouts
When a station fails to reply to a comms command, a 3 second delay is allowed
for the message reply to come back. If at this time no reply has arrived, a two
minute timeout starts during which time the last read will be used by MicroScan.
When the base/remote connection is broken, 30 seconds or longer can be required to allow for the remotes to reconnect, this is why the 2 minute timeout has been selected. If the base and remote startup at the same time, it can take up to 1 minute before a connection will be established.
For large MicroScan sites with existing wired or ethernet stations, the addition of base to remote connections is not recommended if the user wishes to guarantee connection performance of the existing wired stations, as the comms to these stations will be effected because of the normal rate of base to remote to station read speed and if the new remote stations have frequent 3 second timeouts due to bad radio signals. This restriction does not apply if the site wishes to add base/sleeper connections only.