Allen-Bradley PowerFlex400

Application Notes D-5
PID Reference and Feedback
Parameter A152 [PID Ref Sel] is used to enable the PID mode (A152 = 0
“PID Disabled”) and to select the source of the PID Reference. If A152
[PID Ref Sel] is not set to 0 “PID Disabled”, PID can still be disabled by
select programmable digital input options (parameters T051
-T054) such
as “Local” or “PID Disable”.
Table D.A A152 [PID Ref Sel] Options
A153 [PID Feedback Sel] is used to select the source of the PID
feedback.
Table D.B A153 [PID Feedback Sel] Options
Option Description
0 “PID Disabled” Disables the PID loop (default setting)
1 “PID Setpoint“ Selects Exclusive Control. A157
[PID Setpoint] will be used to
set the value of the PID Reference
2 “Analog In 1” Selects Exclusive Control. Selects the Analog In 1 Input.
3 “Analog In 2” Selects Exclusive Control. Selects the Analog In 2 Input. Note
that the PID will not function with a bipolar analog input. It will
ignore any negative voltages and treat them like a zero.
4 “Comm Port” Selects Exclusive Control. The reference word from a
communication network (see Appendix
E for details on the
reference word) such as Modbus RTU or DeviceNet becomes
the PID Reference. The value sent over the network is scaled
so that P035
[Maximum Freq] x 10 = 100% reference. For
example, with [Maximum Freq] = 60 Hz, a value of 600 sent
over the network would represent 100% reference.
5 “Setpnt, Trim” Selects Trim Control. A157
[PID Setpoint] will be used to set
the value of the PID Reference.
6 “0-10V, Trim” Selects Trim Control. Selects the 0-10V Input. Note that the
PID will not function with a bipolar analog input. It will ignore
any negative voltages and treat them like a zero.
7 “4-20mA, Trim” Selects Trim Control. Selects the 4-20mA Input.
8 “Comm, Trim” Selects Trim Control. The reference word from a
communication network (see Appendix
E for details on the
reference word) such as Modbus RTU or DeviceNet becomes
the PID Reference. The value sent over the network is scaled
so that P035
[Maximum Freq] x 10 = 100% reference. For
example, with [Maximum Freq] = 60 Hz, a value of 600 sent
over the network would represent 100% reference.
Option Description
0 “Analog In 1” Selects the Analog In 1 Input (default setting).
1 “Analog In 2“ Selects the Analog In 2 Input. Note that the PID will not
function with a bipolar analog input. It will ignore any negative
voltages and treat them like a zero.
2 “Comm Port” The reference word from a communication network (see
Appendix
E for details on the reference word) such as Modbus
RTU or DeviceNet becomes the PID Feedback. The value sent
over the network is scaled so that P035
[Maximum Freq] x 10 =
100% Feedback. For example, with [Maximum Freq] = 60 Hz, a
value of 600 sent over the network would represent 100%
Feedback.