Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 48)

Programming
Chapter 3
3Ć5
Figure 3.3
Block File Memory Requirements
1 Standard Loop 1 Expanded Loop 2 Standard Loops 2 Expanded Loops
Dynamic
Block
10 Words
Dynamic
Block
10 Words
Loop 1 Constants
Block
12 Words
Loop 1
Constants
Block
19 Words
Status Block
11 Words
Status Block
11 Words
Dynamic
Block
17 Words
Dynamic
Block
17 Words
Loop 1 Constants
Block
12 Words
Loop 2 Constants
Block
12 Words
Loop 1
Constants
Block
19 Words
Loop 2
Constants
Block
19 Words
Status
Block
18 Words
Status
Block
18 Words
11095
Load/Enter Sequence
The load/enter sequence is used when all PID control parameters
(dynamic block and loop block data) are transferred from the PC
processor to the PID module. The load/enter sequence is required at
power-up and whenever it is necessary to change any of the loop
constants in LP1 or LP2 or selected control bits in the master control
word. (After a load/enter sequence has been completed, dynamic block
data can be changed at any time by a write block transfer). Changes to
loop constants require a load/enter sequence as a safety consideration to
prevent inadvertent changes which could adversely affect the system.