Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers - Manual (Page 167)

Publication 1785-UM012D-EN-P - July 2005
Communicating with Devices on a Serial Link 10-17
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:
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.
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.
This Word in a Poll File Contains this Information
Word 0 total number of stations in the list
Word 1 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.
Word 2 through word xx remote station address in the order that the station should be
polled
IMPORTANT
Station addresses are octal addresses. The poll files are
integer files. The default radix is decimal. To properly
enter station addresses in a poll file, you must either:
•
change the radix of the file to octal
•
convert the octal station addresses to decimal before
entering the addresses
Poll File Word 0 Word 1 Word 2
N: xx total number
of stations pointer showing the
station address being
polled
(Station 12 in word 4
is being polled.) address of first station
in list
Word 3
address of second
station in list
Word 4
address of third
station in list
N:11 08 09 10 3 3