Galil DMC-3425 user manual Amplifier Interface, Uncommitted Digital Inputs

NOTE: The effect of an Abort input is dependent on the state of the off-on-error function 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-1460 or AMP-1460 as IN1 – IN3 for the DMC-3425 and IN1 – IN7 for the DMC-3415. The inputs can be accessed directly from the 37 Pin-D cable or connector on the controller, also. For a description of the pinouts, consult the appendix.

These inputs can be interrogated with the use of the command TI (Tell Inputs), the operand _TI, the function @IN[n] and the distributed I/O command TZ. All of these commands may be used locally to address individual controllers, or globally through the distributed control network. See Chapter 4 for a discussion of Global vs. Local communication as it pertains to I/O of the control system.

NOTE: For systems using the ICM-1460 or AMP-1460 interconnect module, there is an option to provide opto-isolation on the inputs. In this case, the user provides an isolated power supply (+5V to +24V and ground). For more information, see the section “Opto-Isolation Option for ICM-1460” in the Appendix of this manual, or consult Galil.

Amplifier Interface

The DMC-3425 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-3425 also provides an amplifier enable signal, AEN. This signal is activated 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.

Note: For a controller ordered as a DMC-3425-Stepper, the amplifier enable signal is used for the second stepper output.

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-1460 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 jumper on the ICM/AMP-1460. When JP1 has a jumper from “AEN” to “5V” (default setting), the output voltage is 0-5V. To change to 12 volts, pull the jumper out and rotate it so that it connects the pins marked “AEN” and “+12V”. If the jumper is removed entirely, the output 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 jumper JP1 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

DMC-3425 Chapter 3 Connecting Hardware• 39