Automation Direct DL05 User Manual page 93

Chapter 8: PID Loop Operation
You may optionally configure each loop to access its analog I/O (PV and control output) by
1
placing proper values in the associated loop table registers in your RLL program. The
following figure shows the loop table parameters at V+36 and V+37 and their auto transfer
2
role to access the analog values directly.
Setpoint V+02
3
4
5
V2036
V2037
6
7
8
When these loop table parameters are programmed directly, a value of "0F02" in register
V2036 directs the loop controller to read the PV data from channel 1 of the analog input. A
9
value of "0000" in either register tells the loop controller not to access the corresponding
analog value directly. In that case, ladder logic must be used to transfer the value between the
analog input and the loop table.
10
NOTE: When auto transfer to/from I/O is used, the analog data for all of the channels on the analog module
11
cannot be accessed by any other method, i.e., pointer or multiplex.
SP/PV Addresses
12
An SP/PV dialog will be made available to setup how the setpoint (SP) and the process
variable (PV) will be used in the loop. If this loop is the minor loop of a cascaded pair, enter
13
that control output address in the Remote SP from Cascaded Loop Output area. It is sometimes
desirable to limit the range of setpoint values allowed to be entered. To activate this feature,
check the box next to Enable Limiting. This will activate the Upper and Lower fields for the
14
values to be entered. Set the limits around the SP value to prevent an operator from entering a
A
B
C
D
8–30
DL05 Micro PLC User Manual, 6th Edition, Rev. A
Error
Process Variable V+03
Loop Table
0F XX Slot / channel number for PV
0F XX Slot / channel number for Output
0F XX
Channel number, 1 to 4
Option Module Slot
Control output V+05
Loop
Calculation