Bootloader Mode; Normal Operation; Safe State; Power On Self Test (Post) - Danfoss PLUS+1 JS1-H User And Safety Manual

User and Safety Manual
PLUS+1® JS1-H Steer by Wire
Steer by Wire Joystick

Power on self test (POST)

Out of range detection

14 | © Danfoss | December 2022

Bootloader mode

On power-up, JS1-H Steer by Wire will automatically enter the Bootloader Mode. Each MCU scans its
memory for installed application software. If detected, the bootloader will start the software and the
joystick will run in Normal Operation.
If no software is installed, the affected MCU will remain in Bootloader Mode. This can be verified by
checking the Danfoss PLUS+1

Normal operation

In Normal Operation, the joystick performs all its operations as described in
taking inputs and converting them to corresponding CAN messages.
Before starting the regular processing, the software performs a self-test. If at least one of the test steps
fails, the joystick will enter the Safe State.

Safe state

JS1-H Steer by Wire enters a Safe State whenever it detects an error. The software reacts to those errors
by taking specified actions in accordance to the error classification.
By design, JS1-H Steer by Wire offers only limited performance in Safe State. Critical or affected modules
are disabled, but the joystick stays operational.
A Safe State can only be reset through a power-cycle. This means, the one-time occurrence of a single
error leads to entering the Safe State. Recovering the error does not bring the joystick back to Normal
Operation.
In order to perform POST during start up the joystick is dependent on stable supply voltage, POST is
triggered by the EHD. When EHD exits "Safety Check" the joystick performs POST on Force Feedback and
Operator Notification.
When the internal logic power supply is stable the joystick will output a valid steering angle independent
of the POST status.
The "Out of range detection" is comparing the Axis sensor input voltage to the max value.
If the input voltage is above the respective max value the joystick reports an error on Channel A.
Channel B will continue to transmit valid steering angle, making it possible to run the system at a
degraded level.
If the input voltage returns to valid range, Channel A will clear the error and report valid steering angle.
® Service Tool.
Joystick overview on page 8,
AX436683569858en-000101