Step 8. make connections to amplifier and encoder – Galil DMC-2X00 User Manual

Page 32

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Step 8. Make Connections to Amplifier and Encoder.

Once you have established communications between the software and the DMC-2x00, you are ready to
connect the rest of the motion control system. The motion control system typically consists of an
ICM-2900 Interface Module, an amplifier for each axis of motion, and a motor to transform the current
from the amplifier into torque for motion.

If you are using an ICM-2900, connect it to the DMC-2x00 via the 100-pin high density cable. The
ICM-2900 provides screw terminals for access to the connections described in the following
discussion.

2x80

Motion Controllers with more than 4 axes require a second ICM-2900 and 100-pin cable.

System connection procedures will depend on system components and motor types. Any combination
of motor types can be used with the DMC-2x00. If sinusoidal commutation is to be used, special
attention must be paid to the reconfiguration of axes.

Here are the first steps for connecting a motion control system:

Step A. Connect the motor to the amplifier with no connection to the controller. Consult the

amplifier documentation for instructions regarding proper connections. Connect and turn-on
the amplifier power supply. If the amplifiers are operating properly, the motor should stand
still even when the amplifiers are powered up.

Step B. Connect the amplifier enable signal.

Before making any connections from the amplifier to the controller, you need to verify that
the ground level of the amplifier is either floating or at the same potential as earth.

WARNING: When the amplifier ground is not isolated from the power line or when it has a different
potential than that of the computer ground, serious damage may result to the computer controller
and amplifier.

If you are not sure about the potential of the ground levels, connect the two ground signals
(amplifier ground and earth) by a 10 k

Ω resistor and measure the voltage across the resistor.

Only if the voltage is zero, connect the two ground signals directly.

The amplifier enable signal is used by the controller to disable the motor. This signal is
labeled AMPENA for the A axis on the ICM-2900 and should be connected to the enable
signal on the amplifier. Note that many amplifiers designate this signal as the INHIBIT
signal. Use the command, MO, to disable the motor amplifiers - check to insure that the
motor amplifiers have been disabled (often this is indicated by an LED on the amplifier).

This signal changes under the following conditions: the watchdog timer activates, the motor-

off command, MO, is given, or the OE1 command (Enable Off-On-Error) is given and the
position error exceeds the error limit. AMPEN can be used to disable the amplifier for these
conditions.

The standard configuration of the AMPEN signal is TTL active high. In other words, the
AMPEN signal will be high when the controller expects the amplifier to be enabled. The
polarity and the amplitude can be changed if you are using the ICM-2900 interface board. To
change the polarity from active high (5 volts = enable, zero volts = disable) to active low
(zero volts = enable, 5 volts = disable), replace the 7407 IC with a 7406. Note that many
amplifiers designate the enable input as ‘inhibit’.

To change the voltage level of the AMPEN signal, note the state of the resistor pack on the
ICM-2900. When Pin 1 is on the 5V mark, the output voltage is 0-5V. To change to 12 volts,
pull the resistor pack and rotate it so that Pin 1 is on the 12 volt side. If you remove the
resistor pack, the output signal is an open collector, allowing the user to connect an external
supply with voltages up to 24V.

Step C. Connect the encoders

22

Chapter 2 Getting Started

DMC-2X00

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