Powerflex 525 Application without PLC

Can PID function implemented on Powerflex 525 Drive without PLC? Yes it can.

What application can be configured using Powerflex 525 Drive alone?

Allen Bradley Powerflex 525 drive from Rockwell has standard control option like VHZ, Sensorless Vector and Close loop control. Beside that, it has additional control that can be used to handle several application without the need of PLC Control:

*𝗣𝗜𝗗 𝗮𝘀 𝗘𝘅𝗰𝗹𝘂𝘀𝗶𝘃𝗲 𝗖𝗼𝗻𝘁𝗿𝗼𝗹
In Exclusive Control, the PID Output becomes the entire Freq Command. This PID loop control could be used to maintain a process feedback such as pressure, flow, or weight to a desired setpoint

*𝗣𝗜𝗗 𝗮𝘀 𝗧𝗿𝗶𝗺 𝗖𝗼𝗻𝘁𝗿𝗼𝗹
In Trim Control, the PID Output is added to the Speed Reference. This PID loop control can be used to maintain the position of Dancer loop etc.

*𝗦𝗽𝗲𝗲𝗱 𝗥𝗮𝘁𝗶𝗼
Used for simple draw applications, like if the next section speed need to be slightly higher or lower speed, than the previous section.

*𝗦𝗽𝗲𝗲𝗱 𝗗𝗿𝗼𝗼𝗽
Used to reduce the frequency output based on current. Typically used in load sharing schemes.

*𝗧𝗿𝗮𝘃𝗲𝗿𝘀𝗲
Used to wound roll evenly in winding application by modulate the output frequency around the Set Frequency. Normally used in Synthetic Yarn Winding application.

*𝗣𝗼𝘀𝗶𝘁𝗶𝗼𝗻 𝗰𝗼𝗻𝘁𝗿𝗼𝗹
Used for simple Positioning application that not requred high bandwidth and high torque at low speed. The position setpoint can be from Preset input or StepLogic. This function need Encoder option card.
Example like, Simple conveyor positioning.


Powerflex 525 also have 4 simple logic functions that provide the capability to program simple logic functions without a need separate PLC Controller. These are Velocity StepLogic, Basic Logic, Timer and Counter Function. Please refer to the User manual for detail.


Supported Hardware on drive:

Embedded Ethernet I/P and Modbus RTU Communication ( Yes, HMI that have modbus RTU, can control this drive)

Isolated 4-20mA, 0-10VDC Analog Input, 7 Digital Input (Sink/Source), 1 Analog Output, 2 Relay Output and 2 Opto Output,

Safety Torque Off Input .

Encoder Card, Profibus, DeviceNet Communication available as an option

Integral Braking Transistor.

Please not, that eventhough Powerflex 525 drive can be used for several application, but this drive not suitable for direct Torque / Tension Control application. Also not suitable for application that required high performance Vector Control

This compact Powerflex 525 drive also don’t have motoring , regenerative limit and don’t have separate positive negative current limit. You can use standard or high perfomance drive such as Powerflex 755 to do that.