Editing Setpoint signal

Reference signal is a signal that will be used as ''target value'' in control systems. Typical occurrencies of reference signals in GD products are:
* Position reference
* Velocity reference
* Torque reference
I.e. position reference value may be "1234" which could mean a target position of 1234 mm in some linear actuator. Or torque reference of 5.0 could mean that motor is asked to produce 5 Nm torque.
==Physical reference signal types==
Reference signals may have several representations in real world such as:
* [[Analog reference]] signal
* [[Pulse and direction]] signals
* [[PWM]] signal
* Serial communication command

In these cases there will be a conversion between input and output units. For example when using +/-10V reference as velocity reference, the relation betveen input to output types could be 1 Volt per 100 rpm (or any other scale).
==Reference signal characteristics==
{| class="wikitable"
|-
!   !! [[Analog reference|Analog]] !! [[Pulse and direction|Pulse & dir]] or [[Quadrature]] !! [[PWM]] !! Network
|-
| Scale & range || Absolute (limited) || Incremental (infinite) || Absolute (limited) || 
*Absolute (near infinite)
*Incremental (infinite)
|-
| Reference uses in motion control || Torque, velocity || Position, velocity || Torque, velocity || Position, torque, velocity, parameters
|-
| Pros 
||  
* Widely used 
* Easy to measure
|| 
*Widely used 
*Exact
*Noise robust 
|| 
*EMI noise robust 
*Precise
 || 
*High resolution & accuracy
*Reduce wiring
*More functions than just reference
|- 
|Cons
 || 
*EMI noise sensitive
*Offset & gain errors
 || 
*Limited resolution at low frequency
*Need reference zeroing because incremental
|| 
*Various "standards", sometimes incompatible
|| 
*Many standards
*Usually incompatible with other standards
|}