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Rockwell Automation Publication 22C-UM001J-EN-E - January 2017
Appendix D
Application Notes
[PID Feedback Sel] is used to select the source of the PID feedback.
Table 32 - A152 [PID Ref Sel] Options
Option
Description
0 “PID Disabled”
Disables the PID loop (default setting)
1 “PID Setpoint“
Selects Exclusive Control. <
> [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
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
[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.
[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
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
[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.
Table 33 - A153 [PID Feedback Sel] Options
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
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
Feedback. For example, with [Maximum Freq] = 60 Hz, a value of 600 sent over the
network would represent 100% Feedback.
3 “ACT1 - ACT2”
Selects actual inputs
[ACT1 Input] minus
[ACT2 Input] to be used as the
feedback signal.
4 “ACT1 + ACT2”
Selects actual inputs
[ACT1 Input] plus
[ACT2 Input] to be used as the
feedback signal.
5 “ACT1 * ACT2”
Selects actual inputs
[ACT2 Input] to be used
as the feedback signal.
6 “ACT1 / ACT2”
Selects actual inputs
[ACT2 Input] to be used as
the feedback signal.
7 “Min A1, A2”
Selects the smaller of actual inputs
[ACT1 Input] or
[ACT2 Input] to be
used as the feedback signal.
8 “Max A1, A2”
Selects the larger of actual inputs
[ACT2 Input] to be used
as the feedback signal.