Sevcon Dragon8 User Manual

System design
Doc. # 177/52705
Rev. 1.0
75
• Set the divisor (object 2915
h
sub index 2) to a known speed point of the motor
• Set the multiplier (object 2915
h
sub index 1) to the corresponding scaled vehicle speed for the
known motor speed.
For example, if it is known that 1000rpm on the motor results in a vehicle speed of 5kph, then the
divisor should be set to 1000, and the multiplier should be set to 0x0050, which is 5kph in Q4 format.
The same process should be repeated for the user speed ratio, setting the multiplier for the user speed in
the desired custom format. Both the vehicle and user speeds, objects 0x2921 and 0x2922, can be mapped
to TPDO for transmission to other devices via CAN if required.
Distance Calculation
Total vehicle distance and trip distance counters are available at objects 0x29A0 and 0x29A1. Counters
will operate and will be accurate provided that the vehicle speed calculated at object 0x2721 is in kph in
12.4 format. Counters are available in the following formats:
• Distance travelled in km in 24.8 format
• Distance travelled in km in 0.1km/bit increments
• Distance travelled in miles in 0.1mile/bit increments
Both distance counters objects can be mapped to TPDOs for monitoring over the CANbus, or for use by
a dashboard display. The trip distance counter can be reset by holding the reset switch, object 0x217D,
closed for 1 second. The total vehicle distance counter cannot be reset by the user.
Service Indication
The controller can reduce vehicle performance and indicate to the operator when a vehicle service is
required. The interval between services is user-configurable.
Configure the following at object 2850
h
:
• Service indication: via an analogue (contactor) output (e.g. to drive a dashboard lamp) and/or
Dragon8’s LED.
• Source hours counter: selects the hours counter and is used to determine when a service is required.
• Service interval: hours between vehicle services. Can be used by the reset function (see below) or for
information only.
• Next service due: Servicing is required when the source-hours counter reaches this time. This can
be set manually, or automatically using the reset function; see below.
• Reset function: write to the reset sub-index at 2850
h
to automatically reset the service timer for the
next service. The next service due time is calculated as the source hours counter time plus the
service interval.
Service profile
This is a drivability profile where you can set maximum torques, speeds and acceleration rates to be
applied when a vehicle needs servicing (2925
h
). See ‘Driveability profiles’ on page 64.
Traction motor cooling fan
This object can be used to drive a motor cooling fan when the operator is present on the vehicle (as
indicated by the seat switch). The cooling fan object (2421
h
) must be mapped to an analogue output.

Sevcon Dragon8 Specifications

General

Brand	Sevcon
Model	Dragon8
Category	Controller
Language	English