Rockwell Automation 1771-KA2 Communication Adapter Module - Manual (Page 62)

Communication Zone Rungs
Chapter 5
5-10
This format uses 3 GET statements. The address position of the first GET
statement lists a remote station data table word. The specified command
operation begins at this memory location. The second and third GET
statements define the starting and ending boundaries of the data table
words in the local station processor. These words are the beginning and
ending data table locations for the words to be transferred in the write or
read operation.
In write operations, data words are written to a remote station from the
local station data table. For a write command, the first GET element in the
command rung lists a beginning address at the remote station. Data is to
be written into this word, and succeeding words from the local station
data table. The second and third GET elements in this type of rung list
starting and ending boundaries for the word or words to be written from
the local station data table.
In a read operation, data words are read from a remote station processor
into the local station data table. The first GET element in the unprotected
read command rung lists the beginning address from which data is to be
read. Remote data table words are read in succession, beginning with this
address. Words are read only into the area of the local data table bounded
by the second and third GET elements in the rung.
Only one set of GET instructions, as shown in Figure 5.6, can be
programmed in a single command rung.
Bit Command Format
When the command code specifies a protected bit write or unprotected bit
write command, use the format shown in Figure 5.7.