Set PIDStepL Motor, Minimum Pulse, and Break Times in PCS 7
For PIDStepL, the PCS 7 APL V7.1 manual defines MotorTime as motor manipulating time [s], PulseTime as minimum pulse time [s], and BreakTime as minimum break time [s]. These settings constrain a step controller's actuator timing, but exact Open/Close command behavior depends on the installed APL release, controller mode, cyclic sample time and position feedback. Confirm the matching manual and actuator limits before changing values.
Table of Contents
- Parameter meanings
- How the settings affect the actuator commands
- Choose values from the actuator and project data
- Verification
- Limitations and Operational Precautions
- Engineer FAQ
- Technical References
- Related Articles
- Related Tags
Parameter meanings
The opened PCS 7 APL V7.1 manual lists MotorTime as motor manipulating time [s], PulseTime as minimum pulse time [s], and BreakTime as minimum break time [s]. It documents PIDStepL as a step controller that can operate with or without actuator-position feedback and identifies the Open, Close and Stop outputs. The ticket does not state its APL version, so confirm names and behavior in the manual for the installed library.
How the settings affect the actuator commands
At a functional level, MotorTime must correspond to the actuator travel time used by the configured control loop. PulseTime and BreakTime constrain the durations/gaps of the step commands. Changing them can alter the shortest Open/Close command and the interval before a subsequent pulse. This is an engineering interpretation of the parameter definitions; the exact output timing algorithm and effect depend on installed APL version, cyclic sample time, controller mode, direction, limits and whether Rbk feedback is used.
Choose values from the actuator and project data
- Identify the exact PIDStepL library/version and whether position feedback is configured.
- Obtain the actuator's documented full travel time and minimum allowable command pulse/break values.
- Check the block's accepted values and SampleTime-related constraints in the matching APL manual.
- Review how Open/Close and Stop are wired to the actuator and any interlocks/feedback.
- Change one parameter at a time under approved testing; do not infer values from the faceplate labels alone.
Verification
Trend or monitor Open, Close, Stop, position feedback and manipulated value in an approved test condition. Confirm command direction, observed actuator travel and timing satisfy the valve/motor specifications and process constraints. A numeric setting change alone does not establish correct actuator behavior.
Limitations and Operational Precautions
The opened Siemens manual is APL V7.1; the source only says APL, with no release, SampleTime, feedback mode or current parameter values. It cannot establish precise timing for the user's block. Changing a step controller affects physical actuator commands; validate in a safe condition and follow the plant's change and interlock procedures.
Engineer FAQ
Does increasing MotorTime make the motor run longer? The V7.1 manual calls it motor manipulating time, but exact control behavior depends on block mode and feedback; verify the installed manual and actuator configuration.
Do PulseTime and BreakTime have interchangeable effects? No. The manual defines one as minimum pulse time and the other as minimum break time.
Technical References
- PCS 7 Advanced Process Library V7.1 Function Manual, 03/2009, A5E02102723-01, section 4.8 PIDStepL, especially I/O definitions pp. 519–523 and controller outputs; official Siemens PDF opened and read.
- PCS 7 Advanced Process Library V9.1 SP1 Function Manual, section 6.10 PIDStepL; large PDF could not be retrieved by the research tool, so V7.1 details were not generalized to V9.1.