Is this correct in English? - Page 1
Forum section: electronics / general

author: TomFy
author_rank: Newbie
timestamp: August 02, 2023, 03:43:34 pm
content: Hi there,there is a fail-safe concept, that has a very special term in German. Several German companies seem to use a literal translation to English and I believe that this translation is wrong. Perhaps some native English speakers can comment?The translation isquiescent current principle. Does that mean anything in English? What it is supposed to mean is a fail-safe concept, where e.g. an alarm contact would be closed when inactive. A broken wire would be detected, because it is equivalent to the contact opening and thus activating the alarm.What would be the correct technical term?

author: 2N3055
author_rank: Super Contributor
timestamp: August 02, 2023, 03:57:50 pm
content: In alarm industry it is called supervised loop..

author: themadhippy
author_rank: Super Contributor
timestamp: August 02, 2023, 04:11:12 pm
content: Quotein the uk we'd call it an anti tamper loop

author: floobydust
author_rank: Super Contributor
timestamp: August 02, 2023, 05:33:07 pm
content: Another way to search is the 'end-of-line resistor' which sets the ("quiescent") amount of loop current. This is to provide "zone supervision"."... to provide zone supervision e.g. allow the field processor to supervise the field wiring for open or short circuit conditions."

author: langwadt
author_rank: Super Contributor
timestamp: August 02, 2023, 06:33:53 pm
content: for limit switches and such, normally closed?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 02, 2023, 07:13:06 pm
content: Other than the suggestions above, I can think of no term to describe the condition.But perhaps I am not understanding the concept. It seems the idea is to make the desired detection condition have the same result as a fault condition, hence some action is always taken if a fault occurs. But this is only meaningful if there is a dominant fault condition. In the stated example if the switch were to close when the protected door/window opens an open would prevent detecting the event. But if the switch opens when the window/door opens a short would prevent detecting the event. Thus having a normally closed switch is only "fail-safe" if opens are the dominant failure mode. Depending on the specific installation this may not be true. A short caused by a nail or screw being driven through the wiring may be more likely than opens due to thermal cycling or rodent damage. More robust fault detection methods are available, but I know of no single word english description that identifies a specific approach.

author: langwadt
author_rank: Super Contributor
timestamp: August 02, 2023, 07:23:39 pm
content: Quote from: CatalinaWOW on August 02, 2023, 07:13:06 pma 4-20mA current loop sorta has it build in. less than 4mA, likely broken wires. More than 20mA, likely shorted wires. 4-20mA, valid signal

author: hans
author_rank: Super Contributor
timestamp: August 02, 2023, 07:25:02 pm
content: "Quiescent" sounds wrong to me. It sounds like the static current of a circuit under no load."Principle" sounds a bit formal.I'm not sure what industry or exact application it is, but it looks similar to 4-20mA current loops. A broken wire in the loop would get detected as 0mA, and thus a fault condition from its operational values.I don't think its necessary to use much more wording than current loop. You could describe an intrusion sensor as a normally closed loop, where any conductor interruption will trigger the system.

author: Someone
author_rank: Super Contributor
timestamp: August 02, 2023, 10:01:45 pm
content: Quote from: TomFy on August 02, 2023, 03:43:34 pmThis usually goes hand in hand with safety integrity levels and how many faults are permissible before the system is unable to operate or identify the fault.The translation makes sense after squinting, in context it is probably acceptable. To rewrite it in English might be something like:passive current systemresting impedance method

author: Tomorokoshi
author_rank: Super Contributor
timestamp: August 05, 2023, 02:51:50 am
content: What is the actual German word?Does this word appear in the German translation of an IEC standard?

author: Stray Electron
author_rank: Super Contributor
timestamp: August 05, 2023, 04:31:37 am
content: Quote from: CatalinaWOW on August 02, 2023, 07:13:06 pmGenerically those conditions are described as a "false negative" or a "false positive" and those terms are used in many industries, particularly in testing. Literally in all kinds of testing; including medical test, drug testing, electronics testing, etc, etc. You can find descriptions of both terms on Wikipedia and in many other places. That's not a one-word description but it's the closest thing that I know of.

author: coppercone2
author_rank: Super Contributor
timestamp: August 07, 2023, 05:51:21 am
content: as far as I know it would be referred to as-open and short circuit detect capabilitybut yeah germany is known for making mega wordsis it called Unterbrkurzsechungennachweisen

author: Haenk
author_rank: Super Contributor
timestamp: August 07, 2023, 01:12:54 pm
content: Quote from: CatalinaWOW on August 02, 2023, 07:13:06 pmThe intention is to detect a cut wire (in alarm systems). So essentially you create a tri-state wiring: open (door/window switch is open, when door/window is opened - or when the wire is cut), short (that would be an error state) and resistance (loop completed and intact). The "open" condition should raise an alarm (when armed), the "short" should create an error.We have this kind of installation in our office, and the yearly service includes disconnecting the devices (PIR sensors, contacts) and measuring the loop.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 08, 2023, 03:52:13 am
content: Quote from: Haenk on August 07, 2023, 01:12:54 pmWith that in mind I don't think there is a single word description (or English compound word) that fully describes it. A current loop comes close, but there are applications of current loop that don't categorize fault states. Your paragraph is about as short as it gets.I would also comment that if this approach is so widely used in Germany that a single word description has proved useful it would also seem that those in the habit of defeating such systems would be well aware of the needed bypass resistance required to stay in limits (a value chosen to not break the low limit when installed and not trip the high limit when the wire is cut. If the limits are set tightly to prevent this approach it would increase manufacture and installation costs, increase false alarms and still be susceptible to a more sophisticated bypass that cut the wire and inserted resistance at the same time. Then you end up discussing how sensitive the glitch detection can be made while not triggering on every motor start, lightning strike and load switch in the area.

author: EPAIII
author_rank: Super Contributor
timestamp: August 09, 2023, 06:40:52 am
content: Am I reading this wrong? You seem to say:1. "open (door/window switch is open, when door/window is opened - or when the wire is cut)"2. "short (that would be an error state)"3. "and resistance (loop completed and intact).The "open" condition should raise an alarm (when armed), the "short" should create an error."I inserted the spaces and numbers for clarity. Conditions 1 would seem to be both alarm and error states. And condition 2 would also be an error state.I would think that two arrangements would be possible:First, with the door and window switches in series and using the NC (normally closed) contacts to indicate they are closed. And a termination resistor at the end of the line.1. Loop shows resistance to indicate all wires are OK and doors and windows are closed.2. Loop shows open to indicate alarm due to open door or window or cut wire.3. Loop shows short to indicate short as an attempt to bypass the security. This would also be an alarm condition.Second, and perhaps a better arrangement with door and window switches in parallel and using the NO (normally open) contacts to indicate they are closed. And a termination resistor at the end of the line.1. Loop shows resistance to indicate all wires are OK and doors and windows are closed.2. Loop shows open to indicate a cut wire.3. Loop shows a short to indicate an alarm due to an open door or window.The problem with the second arrangement is that the individual door or window switches can be disconnected without cutting the loop by bypassing the connections to and from the switch before cutting them from the switch.No system is perfect.Quote from: Haenk on August 07, 2023, 01:12:54 pm

author: Someone
author_rank: Super Contributor
timestamp: August 09, 2023, 07:18:40 am
content: Quote from: EPAIII on August 09, 2023, 06:40:52 amOnly to find a high integrity installation then uses multiple arrangements in parallel to cover each others limitations.

author: tooki
author_rank: Super Contributor
timestamp: August 09, 2023, 12:34:11 pm
content: Quote from: Tomorokoshi on August 05, 2023, 02:51:50 amRuhestromprinzip(In contrast withArbeitssstromprinzip.)The logic of the term Ruhestromprinzip is that it describes that current flows when the circuit is “at rest” (Ruhe=quiet) in contrast with Arbeitsstromprinzip, where circuit flows when the circuit is active (Arbeit=work).The linguistic problem is that theseparate(and more common) word “Ruhestrom” means “quiescent current” and “bias current”, neither of which is relevant to fail-safe circuits.

author: Marco
author_rank: Super Contributor
timestamp: August 09, 2023, 07:57:14 pm
content: It seems to me the closest equivalent is Initiating Device Circuit.