Cw/Ccw (Up/Down) Counting; Encoder Follower (Master/Slave) - Servotronix CDHD2S User Manual

Operations

7.6.2 CW/CCW (up/down) counting

In a CW/CCW (or up/down) system, a pulse on one signal increases motor position, while a
pulse on the other signal decreases motor position. The signal must be connected to the controller
interface (C2).
When a pulse signal is applied to the A channel, the external position counter (PEXT) is
incremented and the motor is rotated in the positive direction. When a pulse signal is applied to
the B channel, the external position counter (PEXT) is decremented and the motor is rotated in the
negative direction. Line frequency and gearing relationships determine the velocity and amount of
shaft movement.
Set GEARMODE to 2 and inform the drive to receive signals via the pulse and direction
⚫
inputs on the control interface (C2).

7.6.3 Encoder follower (master/slave)

In encoder follower mode, the drive follows the quadrature encoder signal generated by the
master. The direction of movement is determined by quadrature signals (A is ahead of B, or B is
ahead of A).
For example, the master device could be a handwheel, a machine main encoder (connected to
the main camshaft), or the equivalent encoder output of another servo drive.
If the master device is a handwheel or a main encoder, after setting XENCRES equal to the
encoder resolution (before quadrature) and setting the gear ratio to 1, the motor will rotate once
for each input revolution.
For example, assume that the handwheel resolution is 120 lines per revolution (i.e., 480 counts
after quadrature). After setting GEARIN=1, GEAROUT=1 and XENCRES=120, the motor will rotate
once every turn of the handwheel.
Quadrature signals can be connected to the controller interface (C2) or the machine interface
(C3). The GEARMODE parameter informs the drive the interface to which the signal is connected.
Set GEARMODE to 0 and inform the drive to receive signals via the pulse and direction
⚫
inputs on the controller interface (C2).
Note that the controller interface (C2) cannot provide voltage to the handwheel or
the main encoder of the machine.
Set GEARMODE to 3 and inform the drive to receive signals through the secondary
⚫
encoder input on the machine interface (C3).
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