Allen-Bradley PLC-5 User Manual page 167

Poll File Word 0
N:11 3
N: xx
total number
of stations
To create station lists, place each station address in an individual word in a poll
file (normal and/or priority) starting at word 2. The poll file layout is as
follows:
This Word in a Poll File
Word 0
Word 1
Word 2 through word xx
To place a station address in a poll file, do the following:
1. Access the data monitor in your programming software.
2. Specify the address of the integer file that is either the normal poll file
or priority poll file (e.g., if the normal poll file is N11, then you specify
N11:0).
3. Enter the station addresses of the remote stations you want in the poll
list starting at word 2. Put them in the order you want them polled.
Station addresses are octal addresses. The poll files are
IMPORTANT
integer files. The default radix is decimal. To properly
enter station addresses in a poll file, you must either:
Below is an example of a station list containing three stations: octal addresses
10, 11, and 12 have been entered. Station 12 (10 decimal) is being polled.
Word 1
3
pointer showing the address of first station
station address being in list
polled
(Station 12 in word 4
is being polled.)
Communicating with Devices on a Serial Link
Contains this Information
total number of stations in the list
address location (poll offset) of the station currently
being polled
For example: a value of 1 means the station address stored in
word 2 is being polled, 2 means the address stored in word 3 is
being polled, etc.
This word is automatically updated by the master station as a
new remote station is polled.
remote station address in the order that the station should be
polled
change the radix of the file to octal
convert the octal station addresses to decimal before
entering the addresses
Word 2 Word 3
08 09
address of second
station in list
Publication 1785-UM012D-EN-P - July 2005
10-17
Word 4
10
address of third
station in list