I am thinking about buying an engine and it said that is was analog controlled?
SO does that mean that it is DCC or DC?
It would be a DC locomotive. DCC would be Digital.
Analog basically means anything not digital. When you break computereeze down to its smallest elements everything is a 1 or a 0 (on or off) combinations of those numbers can represent anything in binary code so computer speak is “digital”. Any other form of control like changing voltage or listening to an LP record does not involve “digital” representation and is by definition “analog”.
I’ve never heard that one before…
Analog means something that varies by a infinite measurable physical quality. In this case DC voltage.
Analog in many cases refers to something that measures or indicates by position or relative value, the following are analog:
A clock with hands
A mercury thermometer
A phonograph record
The speedometer in most cars.
DC is “analog” because the speed of the motor is controlled by the voltage directly.
DCC is digital because the speed is controlled by a coded message to the engine.
Dave H.
Say the objective is to add 2 to 3.
If you pick up two pennies, then pick up three pennies, and COUNT the results getting five, that is digital.
If you put the results on a scale marked in penny weights, and read (MEASURE) five that is analog. Note that since measurement always involves error, you might actually get 4.9 as the reasult.
Have fun
some really complicated answers here…duh…
Straight DC voltage control. Digital control has added a bit more complication to the model railroad vocabulary.
There are DCC decoders which can work using DC control (analog DC), like the BLI locos and use limited sound features.
Most computers use numbers made up of separate bits. This is digital. (DCC is Diigital command control.)
When I started with computers, one group in the university had an Analog computer that operated by measuring voltage or resistance or something.(Either engineering or science.) It must have had some advantage, possibly because it could achieve any number with no limit on decimal places.
It means DC control.
As the word analog control applies to our hobby, it means that the voltage is a variable voltage level controlled by you and the rheostat of the transformer.
DCC or digital is a voltage that is controlled by a decoder and sends pulses (1’s and 0’s) of a set level to the motor.
The power to the loco motor is varied by the width (or time duration) of the 1’s (This is called pulse width modulation (pwm).) or the number of 1’s in a time period (This is Varible Frequency modulation and is used by the supersonic decoders.)
REX [:)]
Digital is anything to do with computer chips. DCC, or Digital Command Control, puts a computer chip inside the locomotive, allowing you to control it independently of any other loco on the track.
Analog is anything “not digital”, which is this case means plain old DC from the good old days. [:D]
As a former industrial-controls geek, I’d like to point one thing out:
While we use the term “analog” for DC control, it’s not a correct use of the term. In controls, Analog implies an infinitely-variable signal; straight DC control has no signal, only the force of track voltage controlled directly by the operator.
Most of the previous generation of command-control systems (Dynatrol and Onboard, for example) actually were analog control systems using an analog signal to control trains. Why’s it matter? One’s correct, the other isn’t. [}:)]
That said, the hobby industry and the hobby press used this term, so now “analog” is the accepted term for DC control of trains. Such is the way of the evolution of language. The only thing that really bugs me is that we’re left without a convenient term for analog command control, but that’s less and less of an issue as these systems become extinct.
I guess resistance was futile [:I]
B-Dubya, I am pretty sure you are correct.
I liken analog to mean that it is a system of operation where the human perception organs can detect what is happening and the brain can intuitively interpret and intervene. Analog is like the 12-hour watch face with the hands pointing to the time. In digital, the time is shown in digital form, with the numbers changing as time goes on, not hands that sweep.
Phonograph records are a form of analog, because voltage changes, in a scale with very high resolution, arising from the needle pickup responding to vibration due to irregularities on the disk surface comprised an analog signal for amplification. When we went to CDs, the only signal detection was from optical readers that looked, not for irregularities, but only digitized information. In this case, digital is the binary yes/no, or off/on, or 1/0.
So, despite its misnomer, DC trains are controlled by the human perception system wanting feedback to something we do directly, like rotate a knob. In DCC, we push a button, but the controller pats us on the head, saying, “Just leave it to me, okay?” and then transmits a coded, but digital, signal to the loco that replies, “And they get to vote!”
[:D]
Hey, B-Dubya, if this ol’ man remembers right (and that is debateable;o))those old analog systems (Dynatrol, On Board, CTC-80, etc. used to be referred to as CARRIER control rather than COMMAND control. Only since the digital stuff became the standard have we begun to refer to the old stuff as COMMAND control. Of course CVP still produces RAIL COMMAND which is, I believe, CTC-80 on steroids; but applies the COMMAND label to it. No generalization is worth a darn, not even this one!
Cheers,
Ed
B-Dub is right on, if you want to be precise about such things. But I get accused of that WAY too much [:D]
Oh, and resistance isn’t futile, it’s a few ohms. [:D][:D]
–Randy
B-Dubya,
You are correct in distinguishing the differences in DC and Analog control as it applies to Industrial controls. However, it is accurate to say that the track voltage used in MRR “DC” is an analog signal because its DC voltage level can be varied. It doesn’t matter if it’s manual or automatic, continuous or not.
It is not any different than a chemical operator changing the setpoint of a temperature or flow electronic controller. The signal leaving the control module in manual or automatic is a varying level DC voltage determined by the setpoint and will be interfaced with the analog card in a PLC or directly to the field device controller.
REX
[geek]
I disagree - I think it’s quite different, because variable DC output to a motor is a variable electromotive force, not an analog signal. We don’t determine if we’re dealing with digital or analog until after we decide if we’re dealing with force or signal. I’m working from the definition of “force” as the direct application of kinetic or electrical energy, and “signal” as logical input (in this discussion, electrical) causing either logical output (such as from a PLC to a motor starter) or the application of force (such as from the motor starter to the motor). Direct DC output to a motor is not “signalling” the motor to turn any more than my rising hand “signals” a beer glass to rise to my mouth. [:)]
Let’s take your PLC example - if the PLC output goes directly to a motor with nothing in between, that voltage is not a signal. If the output goes to a motor controller that varies its output voltage, then the connection between the PLC and the motor controller is a signal. The input from the encoder or pot to the PLC is also a signal, because the PLC executes a logical function based upon it.
I classify direct DC output to a motor as a force - it’s not “signalling” the motor to turn any more than my rising hand “signals” a beer glass to rise to my mouth. [:)]
[/geek]
As I said, I’ve accepted that this term is going to be used, and you can agree with my logic or not. I just consider it one more misnomer among thousands. [8D]
B-Dubya
DC IS an analog signal. It is a infinitely and continuously variable voltage that doesn’t have steps that are associated with a digital signal which can only increment the voltage represented by the steps determined by the bit-rate of the digital signal and is therefore not infinitely variable. By definition, analog is anything that is not digital, i.e: 1’s and 0’s. No digital signal is infinitely variable, but gets closer as the bit rate goes up. Human beings are analog, our eyes, ears and sense of touch are analog. A TV picture tube is analog, speakers and microphones are analog. The signals from the analog devices (such as a microphone) may be converted to digital on the way to the speaker (and thus to our ears), but MUST be converted back to analog, before we can hear it. A DCC signal is a constant voltage signal modulated by 1’s and 0’s to send commands to the digital decoder which then sends an analog voltage to the DC motor in the locomotive since that is still an analog device much as the speakers in our stereo system.
Tom Mann.
dee see
[quote]
QUOTE: Originally posted by ebriley
if this ol’ man remembers right (and that is debateable;o))those old analog systems (Dynatrol, On Board, CTC-80, etc. used to be referred to as CARRIER control rather than COMMAND control. Only since the digital stuff became the standard have we begun to refer to the old stuff as COMMAND control.
[quote]
I’ve been using CTC-16, etc. from the very beginning (1978ish long before most people had any idea a computer could be smaller than a house, let alone know what digital meant) and they have always been generally called command control. See Model Railroader December 1979 issue. The only time I remember using the word “carrier” was used was when the discussion got technical and we had to distinguish distinguish between the command signal and the power signal.
16 locomotives on the track at the same time without blocks… It was amazing to some people.
I have that system too, and by the way, all the throttles, bus and decoders are digital. It doesn’t have to be DCC to be digital.
Well Geek, I guess we have “fredonia” totally confused if he read our post, but very good discussing this with you. Yes, we have a difference in opinion, but that is what makes a good forum.
FYI: Raising your hand may not make a glass of beer rise to your mouth, but it will get you another beer in a bar.[(-D][(-D][:D]
REX