Encoder Connections - Copley Controls Xenus R10 Manual

Accelnet R22

ENCODER CONNECTIONS

The development kit has 10 kΩ pull-up resistors
on the A,B, and X encoder signal inputs (J2-8, 7,
6). There are no pull-up resistors on the /A, /B,
and /X inputs (J2-15,14,13). Jumpers JP1-A,B,C
connect 121 Ω terminating resistors between the
A-/A, B-/B, and X-/X signal pairs for use with
differential-output encoders.
If single-ended encoders are used, these should be
connected to the A,B, & X inputs and jumpers JP1-
A,B, C must be removed to take the terminating
resistors out of circuit. For motors which use
encoders with differential outputs, jumpers JP1-
A,B,C should be installed to eliminate reflections
that degrade signal quality. For longer distances
between motor and amplifier, and to offset the
effects of cable capacitance, wiring should be
twisted-pair, preferably with a shield for each pair.
Encoder power is supplied from an external +5
Vdc supply with sufficient current to drive the
motor encoder. Typically these will be 250 mA or
less. In cases where an encoder uses a separate
interpolater module to process the data, current
demand may be higher. Consult the motor encoder
literature to be sure that the +5 Vdc supply can
handle the encoder power requirements.
9
21
8
20
7
19
J3
SIGNAL
Copley Controls, 20 Dan Road, Canton, MA 02021, USA
Tech Support: E-mail: sales@copleycontrols.com, Internet: http://www.copleycontrols.com
POWER SUPPLIES
Amplifier main power, +HV, is typically supplied
by unregulated DC power supplies. These must be
isolated from the mains, and all circuits should be
grounded to earth at some point.
The +HV supply connects to J1. Pin J1-5 is the +HV
positive terminal, and pin J1-4 is the power supply
negative terminal that connects to circuit ground.
For good wiring practice, the HV wires should be
twisted together for noise suppression, and the
power supply should not be grounded. Doing
this ensures that the higher currents flowing in
these conductors will not flow through any circuit
grounds where they might induce noise.
During deceleration, mechanical energy in the
motor and load is converted back into electrical
energy that must be dissipated as the motor
comes to a stop. While some of this is converted
to heat in the motor windings, the rest of it will
flow through the amplifier into the power supply.
An external storage capacitor should be used if
the load has appreciable inertia, and this should
be sized such that adding the undissipated energy
from the motor will not raise the voltage beyond
the point at which the amplifier shuts down.
When this is not possible, an external 'dumper', or
regenerative energy dissipater must be used which
acts as a shunt regulator across the HV terminals.
Switching power supplies can also be used to
power Accelnet. Unlike unregulated supplies, these
cannot accept reverse energy flow, so an isolating
diode must be placed between the power supply
and J1-5 to block current flow back into the power
ENCODER SIGNALS
/X /B /A X B
121
A
121
B
121
C
JP3
8
15
7
14
6
13
J2
ENCODER
RUGGEDIZED DIGITAL
BRUSHLESS/BRUSH MOTORS
Development Kit
A
+5
10k
10k
10k
Tel: 781-828-8090
R22
SERVO DRIVE FOR
supply. When this is done, an external storage
capacitor must be used across J1-5 & J1-4 because
the capacitor on the Development Kit board is only
for ripple-current control, and can't store enough
energy to handle regeneration.
An earthing ground connection can be made via
a second conductor to J1-4 that connects to the
equipment frame ground.
If desired, an Aux HV supply can also be connected
via J8-1 and J8-2. This supply must be greater
than the amplifier minimum supply voltage of
+20 Vdc. Commonly available +24 Vdc supplies
work well for this. Using the Aux HV input enables
the amplifier to have the HV supply turned off
for equipment safety or EMO (Emergency Off)
conditions. At this time, the Aux HV will keep the
amplifier 'alive' and able to communicate and
monitor position, but not to power the motor.
Fax: 781-828-6547
Page 14 of 22
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