RoboteQ Dual Channel Digital Motor Controller AX2550 - Manual (Page 50)

General Operation
50 AX1500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Special Use of Accessory Digital Inputs
The AX1500 includes two general purpose digital inputs identified as Input E and Input F.
When an Encoder Module is installed, input E is disabled. The location of these inputs on
the DB15 connector can be found in the section “I/O List and Pin Assignment” on
page 54, while the electrical signal needed to activate them is shown on “Connecting
Switches or Devices to Input F” on page 56.
By default, these inputs are ignored by the controller. However, the AX1500 may be config-
ured to cause either of the following actions:
• Activate the buffered Output C
• Turn Off/On the power MOSFET transistors
These alternate modes can only be selected using the Roborun Utility (see “Control Set-
tings” on page 165. Each of these modes is detailed below.
Using the Inputs to Activate the Buffered Output
When this setting is selected, the buffered Output C will be On when the Input line is
pulled to Ground (0V). The Output will be Off when the Input is pulled high.
This function makes it possible to drive solenoids or other accessories up to 2A at 24V
using a very low current switch, for example.
Using the Inputs to turn Off/On the Power MOSFET transistors
When this setting is selected, the controller’s Power MOSFET transistors will be active,
and the controller will be operating normally, only when the input is pulled to ground.
When the input is pulled high, all the power MOSFETs are turned Off so that the motors
are effectively disconnected from the controller.
This function is typically used to create a “dead man switch” when the controller is driven
using an analog joystick. The motors will be active only while the switch is depressed. If
the switch is left off for any reason, the motors will be disconnected and allowed to free-
wheel rather than coming to an abrupt stop.