Automating Manufacturing Systems - Process Control and ...

plc basic functions - 15.13
A
AVE
File weight[0]
Dest weight_avg
Control c_1
length 4
position 0
B
STD
File weight[0]
Dest weight_std
Control c_2
length 4
position 0
Addr.
C
before
after A
after B
after C
SRT
File weight[0]
Control c_3
length 4
position 0
weight[0]
weight[1]
weight[2]
weight[3]
weight_avg
weight_std
3
1
2
4
0
0
3
1
2
4
2.5
0
3
1
2
4
2.5
1.29
1
2
3
4
2.5
1.29
Figure 15.12
Statistical Calculations
ASIDE: These function will allow a real-time calculation of SPC data for control
limits, etc. The only PLC function missing is a random function that
would allow random sample times.
15.2.4.2 - Block Operations
A basic block function is shown in Figure 15.13. This COP (copy) function will
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