Curtis 1244 User Manual page 88

APPENDIX A: GLOSSARY
High-pedal-disable (HPD)
The HPD feature prevents the vehicle from driving the motor if the controller
is turned on when greater than HPD threshold throttle is applied. Three types
of HPD are available (along with a "no HPD" option). Selection is made with
the programmer—see Section 3, page 41.
Interlock switch
This switch is a controller-enable input intended to provide a secondary op-
erational interlock for the controller in addition to the keyswitch input. If an
interlock switch is used, it must be closed—providing a high signal to the in-
terlock pin (Pin 2)—in order for the controller to operate. This safety interlock
is used on most material handling vehicles. Cycling the interlock switch or the
keyswitch clears most faults and re-enables operation.
KSI
KSI (Key Switch Input) provides power to the controller's logic board, initializes
the microprocessor, and starts diagnostics. In combination with the interlock
switch input, KSI enables all logic functions.
Load compensation
The load compensation feature automatically adjusts the applied motor voltage
as a function of motor load current. This results in more constant vehicle speeds
over variations in motor loading due to ramps and cargo weights—without the
operator having to constantly adjust the throttle position. The load compensa-
tion parameter is programmable—see Section 3, page 49.
The load compensation and Field Map Start parameters allow the OEM
to tune the vehicle's loaded top speed to approach its unloaded top speed—see
Section 6, pages 60–61.
M- fault detect
This feature determines if the M- power connection is being held low (to B-) by
an internal or external fault condition. If an M- fault is detected, the controller
will inhibit PWM output and release the main and auxiliary contactors. M-
fault detection is not performed if greater than 85% throttle is being requested
or if emergency reverse is activated.
MOSFET
A MOSFET (metal oxide semiconductor field effect transistor) is a type of
transistor characterized by its fast switching speeds and very low losses.
A-6
Curtis 1244 Manual,
Rev. E