User manual
Publication AG-UM008C-EN-P - February 2005
Sample Ladder Logic E-15
The next three rungs create a data file comparison routine. This rung clears the index register (S:24) to prepare it for use in the Not Equal comparison instruction.
0
003
CLR
Clear
Dest S2:24
0<
CLR
Index Register
If any values differ between the first three words of B3:0 and N7:0, copy B3:0-7 into N7:0-7, trigger the MSG (which will write N7:0-7 to the Master) and jump out of the routine.
0
004
LBL
Q2:1
Compare
Rung
NEQ
Not Equal
Source A #B3:0
0000000000000000<
Source B #N7:0
0<
NEQ
Data Compare Buffer
COP
Copy File
Source #B3:0
Dest #N7:0
Length 8
COP
MSG Write Buffer
U
N7:90
15
MSG
Enable
JMP
Q2:2
Jump to
MSG Rung
If the current value comparison found no differences, increment the index register. As long as the index register (S:24) is still less than the number of words being compared, jump back to the previous rung to
perform the next value comparison. Otherwise, fall out of the routine.
0
005
ADD
Add
Source A S2:24
0<
Source B 1
1<
Dest S2:24
0<
ADD
Index Register
LES
Less Than (A<B)
Source A S2:24
0<
Source B 3
3<
LES
Index Register
JMP
Q2:1
Jump to
Compare
Rung
The next two rungs are the MSG rungs. Timer T4:1 is used as the MSG timeout timer, with a preset value of 10 seconds. Note that the MSG timeout value should be set to at least twice the channel 0 poll timeout
value.
0
006
LBL
Q2:2
MSG Rung
N7:90
15
MSG
Enable
N7:90
13
MSG
Done
N7:90
12
MSG
Error
EN
DN
TON
Timer On Delay
Timer T4:1
Time Base 1.0
Preset 10<
Accum 0<
TON
MSG Timeout Timer
T4:1
DN
MSG
Timer
L
N7:90
8
MSG
Timeout
"Report-by-exception" write instruction to the SLC Master. This MSG block is configured to write 8 elements ( words) from this Slave's Source File N7:0, out channel 0, to the Master's (Target Node Address 0)
Target Destination File N7:10. MSG can only be triggered if DF1 is the active protocol.
0
007
S2:0
11
Active
Protocol
EN
DN
ER
MSG
Read/Write Message
Read/Write Write
Target Device 500CP
U
Control Block N7:90
Control Block Length 7
Setup Screen
MSG
Write MSG to Master
0
008
END