Industrial Engineer · phase 8 of 16 · noun
Keypad / HIM
Local operator interface used to view status, edit parameters, issue commands, and read faults.
The Explain card
- Plain English
- The keypad, or human interface module, is the little panel on the front of the drive. It shows status and faults, lets you read and edit parameters, and can start, stop and set speed on its own.
- Example
- A technician pulls up the fault history on the keypad, sees three overvoltage trips at the same time each shift, and knows to look at the deceleration ramp.
- Why it matters
- The keypad is the only view into the drive with no laptop, and on many drives it also holds a copy of the parameters that can be pushed into a replacement. A drive left in keypad control ignores the PLC, which is a common reason a motor will not start.
- Hook
- The front door, and sometimes the only key.
Word knowledge
How the word is built, where it came from, and what it sits beside in memory.
In a sentence
The technician used the keypad to enter the motor nameplate current before commissioning the variable frequency drive.
How it is built
- key compound element a button pressed to enter a command or value
- pad compound element a compact surface or group of controls
Where it came from
- Origin
- an English compound formed from key and pad
- Entered the language
- 1960s
- What changed
- The compound first denoted a compact bank of push keys and later became a common name for built-in control panels on electronic and industrial equipment.
How it is spelled
- Pattern
- It is a closed compound written as one word.
- Pattern
- Each element retains its ordinary spelling: key plus pad.
Spelled like
- keyboard
- keyway
- touchpad
- trackpad
Broken into chunks
-
key
- keyboard
- keyway
- keystroke
-
pad
- touchpad
- trackpad
- notepad
Where it sits in the deck
Phase 8: VFD Drive Hardware and Power Path
Inside the drive: rectifier, DC bus and inverter, the three stages every variable frequency drive uses to rebuild the waveform a motor sees.
