Hook flash

{
  "id": "MLC-T-IND-002875",
  "term": "Hook flash",
  "field": "Industrial and trades",
  "definition": "A brief, momentary interruption of the telephone line, made by tapping the switch hook or pressing a flash or recall key, that signals the exchange or a PBX to perform a function such as switching to a waiting call, placing a call on hold, or transferring a call. North American switches accept a flash of roughly 300 to 1000 ms, while European recall signals are typically a loop disconnect pulse of 100 to 120 ms.",
  "synonyms": [
    "flash"
  ],
  "subject": "Electrical engineering",
  "see_also": [
    "flash"
  ],
  "translations": {
    "de": "Hook Flash",
    "es": "flash de gancho",
    "fr": "flash de décrochage"
  },
  "url": "https://mlchart.com/terminology/industrial/hook-flash/"
}