Rockwell Automation 1775-S5_SR5,D17756.5.5 User Manual PLC-3 FAMILY I/0 - Manual (Page 53)

I/O Communication
Chapter 3
3-5
Programming PeerĆtoĆPeer Communication
Programming PLC-3 family controllers for peer-to-peer communication
requires that the ladder program in the:
master transfers the appropriate data to its output file
receiving slave knows the proper use for each word in its input file
The controller automatically handles the actual data transfer. Each slave’s
input file must be equal to or larger than the master’s output file.
Otherwise, a peer-to-peer communication minor fault occurs.
Figure 3.3 shows an example of the ladder rungs that transfer data to
output file FO001 in the master controller. The rungs that move data into
the output file are unconditional. If they are conditioned, “old” data
transfers whenever the rung conditions are false, because the transfer
occurs regardless of whether the output file is updated.
Figure 3.3
Example Rungs in the Transmitting Controller on a PeerĆtoĆPeer
Communication Channel
CU COUNT UP C0008
CP =
CA =
10
6
DN
01
CTU
MOVE FROM A TO R
A : WCACC:0008
6
R : WO001:005
0000000000000110
MOV
I0001
C0008
17
C0008
15
EN FILES FROM A TO R
A : FB001:0000
R : FO001:0010
COUNTER : C0009
DN
ER
MVF
C0009
12
C0009
12
C0009
12
POS/LEN = 0/ 10
MODE = ALL/SCAN