Danfoss PVED-CLS, User Manual, Page: 12 / 182

12 | © Danfoss | August 2018 AQ00000211
ENGINEERING TOMORROW
1.2 CAN INTERFACE
Danfoss recommends installation of steering related CAN nodes on a separate CAN bus, in order to avoid excessive bus
load. In some situations, particularly when several status messages are enabled, the PVED-CLS and accompanying CAN
nodes may occupy most of the useful bandwidth of a 250K CAN bus.
Danfoss recommend that installation guidelines from CAN bus standard J1939/15 are followed (unshielded twisted pair
(UTP), etc.)
1.3 POWER-UP
During power-up the PVED-CLS will typically complete its boot sequence after ~1800ms. At this time an address claim
message will be issued on the CAN bus. Following the address claim the PVED-CLS will go into WAS calibration service
mode as default (provided that no prior calibrations have been done and PVED-CLS is setup with default parameters).
After the WAS has been calibrated and the PVED-CLS has been power-cycled, PVED-CLS will go into spool dead-band
calibration service mode.
When the spool dead-band calibration is performed and the PVED-CLS has been reset (power-cycle or software-reset) ,
an initialization period of max 10 seconds is started, to allow speed sensor messages, MMI messages, WAS
messages/signal, AUX messages, SASA messages and Road switch signal to boot and appear on the CAN bus or input
pins.
Once in operation mode the CAN messages and analogue signals are periodically validated and must remain present for
the PVED-CLS to remain in operation mode. The validation period is configurable for each signal. In case a mapped
message disappears from the CAN bus, analogue signals are disconnected or signal crosscheck fails, the PVED-CLS will
enter safe state and remain non-operational until a reset is completed. Missing curvature commands are exceptions and
does not put PVED-CLS to safe state. A reset may be either a power cycle sequence or a soft reset CAN message. For
more details, please see the Danfoss document- PVED-CLS communication Protocol.
1.4 CAN BUS PROTOCOL
The PVED-CLS conforms to CAN bus standard J1939. Access to reading is provided through the KWP2000 and PVED-
CLS Communication protocols and modifying configuration parameters is provided through the KWP2000 protocol.
Please see the Danfoss documents, PVED-CLS KWP2000 Protocol and PVED-CLS communication Protocol.
1.5 DC POWER SUPPLY
The PVED-CLS is designed to operate reliably with both 12V and 24V battery voltage, as used on typical agricultural
vehicles. Internal voltage regulators allow fluctuations on supply voltage terminals from 5.5V to 35.5V, but the PVED-
CLS will sent out an INFO level DTC if the supply goes below 9V, but will not enter safe state. Below 9V the
electrohydraulic functions of an EHPS, EHi and OSPE cannot be guaranteed to work properly. In case the supply voltage
exceeds 35.5V, a DTC is issued on the CAN bus, and the PVED-CLS will enter safe state. If the power supply goes below
5.5V the PVED-CLS will shut down.
Experience shows that excessively low supply voltage may occur during engine cranking in cold conditions, depending
on the state of battery charge, and/or general state of battery.