Bradley Smoker PLC-5 user manual Remote stations, Default size is 64 words, Priority poll file

10-16Communicating with Devices on a Serial Link

To define a polling scheme using standard mode, you must specify the following on the DF1 master configuration screen in your programming software:

Configuration Parameter	Definition
Polling mode	How you want the master to poll the station lists.
Master message transmit	When you want the master to send messages.
Normal poll file	An integer file in which you place the station addresses of
	the remote stations.
	The default size is 64 words.
Priority poll file	An integer file in which you place the addresses of stations
	from which you need to collect data more frequently.
	The default size is 64 words.
Normal poll group size	The number of stations that the master polls before it polls a
	station in the priority poll list.
Active station file	A binary file that stores the station addresses of all active
	stations on the link.
	The default size is 18 words.
	Both the normal poll list and the priority poll list can have
	active and inactive stations. A station becomes inactive
	when it does not respond to a master’s request for data.

The master station polls the slave station in the following a definitive sequence:

1.All stations in the active priority poll file.

2.Specified stations in the active normal poll file. The number of stations polled in this file is determined by the normal poll group size specified on the configuration screen. If the group size was 3, for example, then three stations would be polled in the normal file before the master continues to the next step in the sequence.

3.One station in the inactive poll file after all active stations in the normal poll file have been polled.

Publication 1785-UM012D-EN-P - July 2005