Only if there is a device on the receiving end that executes logic based upon the input of that voltage. If the receiving device is a motor, then the DC voltage is not a signal, because the motor has no logic. Voltage does not “signal” a motor to turn, it forces it to turn. If I make a “pushing” gesture to you to indicate you should move back, that’s a signal. If I use the same motion of my arm to push you back, that’s a force. The difference is that in one case, you’re interpreting my movement and acting upon it; in the other my action is physically moving you.
What’s really cool is that a voltage can be signal and force at the same time if it’s connected in parallel to a motor and to a logic device. To the motor it’s a force; to the logic device it’s a signal.
At the end of it all, we’ll keep using the name “Analog” for DC train control, because that’s the most widespread term. Well, this was fun. Back to sleep for me…[zzz]