Uncommitted Digital Inputs; Amplifier Interface - Galil Motion Control DMC-18 2 Series User Manual

NOTE: The effect of an Abort input is dependent on the state of the off-on-error function (OE) for
each axis. If the Off-On-Error function is enabled for any given axis, the motor for that axis will be
turned off when the abort signal is generated. This could cause the motor to 'coast' to a stop since it is
no longer under servo control. If the Off-On-Error function is disabled, the motor will decelerate to a
stop as fast as mechanically possible and the motor will remain in a servo state.
All motion programs that are currently running are terminated when a transition in the Abort input is
detected. For information on setting the Off-On-Error function, see the Command Reference, OE.

Uncommitted Digital Inputs

The general use inputs are TTL and are accessible through the ICM-2900 as XLATCH-WLATCH
(inputs 1-4) and IN5-IN8. These inputs can be interrogated with the use of the command TI (Tell
Inputs), the operand _TI, and the function @IN[n] (see Chapter 7, Mathematical Functions and
Expressions).

Amplifier Interface

The DMC-18x2 analog command voltage, ACMD, ranges between +/-10V. This signal, along with
GND, provides the input to the power amplifiers. The power amplifiers must be sized to drive the
motors and load. For best performance, the amplifiers should be configured for a current mode of
operation with no additional compensation. The gain should be set such that a 10 Volt input results in
the maximum required current. If the controller is operating in stepper mode, the pulse and direction
signals will be input into a stepper drive.
The DMC-18x2 also provides an amplifier enable signal, AEN. This signal is deactivated under the
following conditions: the watchdog timer activates, the motor-off command, MO, is given, or the
OE1command (Enable Off-On-Error) is given and the position error exceeds the error limit. As
shown in Figure 3-1, AEN can be used to disable the amplifier for these conditions.
The standard configuration of the AEN signal is TTL active high. In this configuration the AEN 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 AEN signal, note the state of the resistor pack on the ICM/AMP-
1900 or 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.
To connect an external 24V supply, remove the resistor pack, RP1, from the interconnect board.
Connect a 2.2kΩ resistor in series between the +24V of the supply and the amplifier enable terminal on
the interconnect (AMPEN). Then wire the AMPEN to the enable pin on the amplifier. Connect the -
24V to the ground, GND, of the interconnect and connect the GND of the interconnect to the GND of
the amplifier. NOTE: Before connecting the GND of the interconnect, to the GND of the amplifier,
check for continuity between the two points. If continuity exists, do not connect the two points. If
continuity does not exist, then you must connect the points to create a reference for the motor
command signal.
DMC-18x2
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Chapter 3 Connecting Hardware • 31