NAME

       sim_encoder - simulated quadrature encoder

SYNOPSIS

       loadrt sim_encoder [num_chan=num | names=name1[,name2...]]

DESCRIPTION

       sim_encoder can generate quadrature signals as if from an encoder.  It also generates an index pulse once
       per  revolution.   It  is  mostly  used  for  testing and simulation, to replace hardware that may not be
       available.  It has a limited maximum frequency, as do all software based pulse generators.

       sim_encoder supports a maximum of eight channels.  The number of channels actually loaded is set  by  the
       num_chan=  argument  when the module is loaded.  Alternatively, specify names= and unique names separated
       by commas.

       The num_chan= and names= specifiers  are  mutually  exclusive.   If  neither  num_chan=  nor  names=  are
       specified, the default value is one.

FUNCTIONS

       sim-encoder.make-pulses (no floating-point)
              Generates  the  actual  quadrature and index pulses.  Must be called as frequently as possible, to
              maximize the count rate and minimize jitter.  Operates on all channels at once.

       sim-encoder.update-speed (uses floating-point)
              Reads the speed command and other parameters and converts the data into a form that can be used by
              make-pulses.  Changes take effect only when update-speed runs.  Can (and should)  be  called  less
              frequently than make-pulses.  Operates on all channels at once.

NAMING

       The names for pins and parameters are prefixed as:
         sim-encoder.N. for N=0,1,...,num-1 when using num_chan=num
         nameN. for nameN=name1,name2,... when using names=name1,name2,...

       The sim-encoder.N. format is shown in the following descriptions.

PINS

       sim-encoder.N.phase-A bit out
              One of the quadrature outputs.

       sim-encoder.N.phase-B bit out
              The other quadrature output.

       sim-encoder.N.phase-Z bit out
              The index pulse.

       sim-encoder.N.speed float in
              The desired speed of the encoder, in user units per per second.  This is divided by scale, and the
              result is used as the encoder speed in revolutions per second.

PARAMETERS

       sim-encoder.N.ppr u32 rw
              The  pulses  per  revolution  of the simulated encoder.  Note that this is pulses, not counts, per
              revolution (ppr).  Each pulse or cycle from the encoder results in four counts, because every edge
              is counted.  Default value is 100 ppr, or 400 counts per revolution.

       sim-encoder.N.scale float rw
              Scale factor for the speed input.  The speed value is divided by scale to get the  actual  encoder
              speed in revolutions per second.  For example, if scale is set to 60, then speed is in revolutions
              per minute (RPM) instead of revolutions per second.  The default value is 1.00.

LinuxCNC Documentation                             2007-01-16                                     SIM_ENCODER(9)