Specifications

LA Series Linear Servo Amplifier Technical Reference Manual

5 Operational Description

Before applying power to the amplifier be sure to read all sections in this document.

Upon power up of the +/- 15V bias supply, the amplifier derives all the necessary internal

voltages for operation related to the logic and output drivers. Once the proper levels are achieved, the

DSP is released from reset and begins operation. A series of internal checks are done to insure the DSP

is operating correctly. The I/O is initialized for operation if these checks pass. The NVM is then read and

the stored checksum is verified. If the system is setup to use jumpers, the jumpers are read; otherwise the

parameter information from NVM is used. The analog balance network is set to the stored balance

values. The version and revision number for the software is flashed on the display and the serial sign on

message is sent.

The state of the Enable input is read to determine whether the hardware enable input or the

software serial enable command should be used to enable the drive. If the hardware Enable input is

inactive (disabled state) the system allows software to control the Enable operation via the E command. If

at anytime during operation the Enable input goes active, the software mode is cancelled and the

hardware Enable input is used for control. The "e" command controls the active enable state (as of

version 2.4.0). The initialization process is now complete and the software enters main loop processing.

During main loop processing, the software runs in an endless loop performing the tasks

necessary for drive operation. Once per pass in the main loop, the 7-segment LED and status port are

updated, the inputs are scanned and the protective algorithm calculations are performed. In addition to

the main loop processing, interrupts are enabled to handle such actions as Limit input processing for Hall

mode, A/D processing for all system voltages and currents, and serial communication if used.

If at anytime during operation a fault occurs, the drive will immediately disable the motor

windings, set the Fault output active and display the fault code on the LED display. A message will also

be sent over the serial interface annunciating the fault. The “A” command can also be used to obtain fault

information. The "f" command sets the active level for the fault output (as of version 2.4.0).

Note that bias power (+/-15V) is always required for the drive to operate. Bus power is only

required if a motor is to be used. This allows the drive to be set up away from the actual system using

only the bias supply.