Galil DMC-13X8 user manual Analog Inputs, Amplifier Interface, Bypassing the Opto-Isolation

External Resistor Needed for		External Resistor Needed for
Voltages > 24V	LSCOM	Voltages > 24V	LSCOM

2.2K

2.2K

FLSX

FLSX

Configuration to source current at the	Configuration to sink current at the
LSCOM terminal and sink current at	LSCOM terminal and source current at
switch inputs	switch inputs

Figure 3-2. Connecting a single Limit or Home Switch to an Isolated Supply. This diagram only shows the connection for the forward limit switch of the X axis.

NOTE: As stated in Chapter 2, the wiring is simplified when using the ICM-1900 or AMP-19X0 interface board. This board accepts the signals from the ribbon cables of the DMC-13X8 and provides phoenix-type screw terminals. A picture of the ICM-1900 can be seen in Chapter 2. If an ICM-1900 is not used, an equivalent breakout board will be required to connect signals from the DMC-13X8.

Bypassing the Opto-Isolation:

If no isolation is needed, the internal 5 Volt supply may be used to power the switches. This can be done by connecting a jumper between the pins LSCOM or INCOM and 5V, labeled JP3. These jumpers can be added on either the ICM-1900 (J52) or the DMC-13X8. This can also be done by connecting wires between the 5V supply and common signals using the screw terminals on the ICM- 1900 or AMP-19X0.

To close the circuit, wire the desired input to any ground (GND) terminal or pin out.

Analog Inputs

The DMC-13X8 has eight analog inputs configured for the range between -10V and 10V. The inputs are decoded by a 12-bit A/D decoder giving a voltage resolution of approximately .005V. A 16-bit ADC is available as an option. The impedence of these inputs is 10 KΩ. The analog inputs are specified as AN[x] where x is a number 1 thru 8.

Amplifier Interface

The DMC-13X8 analog command voltage, MOCMD, 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.

The DMC-13X8 also provides an amplifier enable signal, AEN. This signal changes 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 3-3, AEN can be used to disable the amplifier for these conditions.

USER MANUAL Chapter 3 Connecting Hardware • 41