Galil DMC-1700 Connecting Hardware, Overview, Using Optoisolated Inputs, Limit Switch Input, 1X80

Chapter 3 Connecting Hardware

Overview

The DMC-1700/1800 provides optoisolated digital inputs for forward limit, reverse limit, home, and abort signals. The controller also has 8 optoisolated, uncommitted inputs (for general use) as well as 8 TTL outputs and 8 analog inputs configured for voltages between +/- 10 volts.

1X80	Controllers with 5 or more axes have 16 optoisolated uncommitted inputs, 8 TTL inputs, and 16 TTL
	outputs.
17X8	The DMC-1718, 1728, 1738, and 1748 controllers have an additional 64 I/O which can be connected
	to OPTO 22 racks.

This chapter describes the inputs and outputs and their proper connection.

If you plan to use the auxiliary encoder feature of the DMC-1700 or DMC-1800, you must also connect a cable-26- 25 from the 26-pin J5 Auxiliary encoder connector on the DMC-1700 or DMC-1800 to the 25-pin connector on the AMP-19X0 or ICM-1900. This cable is not shipped unless requested when ordering. For controllers with 5 or more axes, two cable-26-25 cables are necessary for connection to two separate interconnect modules.

Using Optoisolated Inputs

Limit Switch Input

The forward limit switch (FLSx) inhibits motion in the forward direction immediately upon activation of the switch. The reverse limit switch (RLSx) inhibits motion in the reverse direction immediately upon activation of the switch. If a limit switch is activated during motion, the controller will make a decelerated stop using the deceleration rate previously set with the DC command. The motor will remain on (in a servo state) after the limit switch has been activated and will hold motor position.

When a forward or reverse limit switch is activated, the current application program that is running will be interrupted and the controller will automatically jump to the #LIMSWI subroutine if one exists. This is a subroutine which the user can include in any motion control program and is useful for executing specific instructions upon activation of a limit switch. Automatic Subroutines are discussed in Chapter 6.

After a limit switch has been activated, further motion in the direction of the limit switch will not be possible until the logic state of the switch returns back to an inactive state. This usually involves physically opening the tripped switch. Any attempt at further motion before the logic state has been reset will result in the following error: “022 - Begin not possible due to limit switch” error.

The operands, _LFx and _LRx, contain the state of the forward and reverse limit switches, respectively (x represents the axis, X,Y,Z,W etc.). The value of the operand is either a ‘0’ or ‘1’ corresponding to the logic state of the limit switch. Using a terminal program, the state of a limit switch can be printed to the screen with the command, MG

DMC-1700/1800 Chapter 3 Connecting Hardware • 43