Reference — Bell Marine gateway

The MUXEN devices this gateway publishes

Device	Function	Instance	What it carries
Motor	7	configured (InstanceNum), default 0	one per discovered propulsion controller: state, speed, temperature, DC voltage and current
Generic I/O	17	configured (InstanceNum)	the box's own inputs, and the state of the two relays the propulsion logic drives

MQTT topics on the Brain follow device/<function>/<instance>/<frame>: a motor numbered 1 publishes on device/7/1/life and takes commands on device/7/1/command.

What a motor publishes

Field	Unit	Where it comes from
state	off / regeneration / drive / error	the controller's reported mode; off also means "silent for 1.5 s"
rpm	rpm, always positive	shaft speed magnitude — direction is not distinguished
temperature	°C	a temperature reported by the controller
voltage	V	DC bus voltage
current	A	DC bus current, sign reversed relative to the controller's convention

What a motor accepts

Sent as JSON on device/7/<instance>/command.

Request	Effect on this gateway
requestRegeneration	closes relay 1 for 5 s; renewed by each further request
requestOff	opens relay 1
requestDrive, requestRegulatorSpeed, requestRegulatorPower, setpoint	accepted and ignored — they release relay 1 and do nothing else

Nothing is ever transmitted on the propulsion bus. Every request this gateway acts on leaves the box as a relay contact.

The two relays

Relay	Closed when
1 — regeneration request	the boat asked for regeneration within the last 5 s; open otherwise
2 — power limitation	the bound battery bank is missing, off, overloaded or low — including at power-up, before a healthy bank has been seen

Neither can be commanded from the MUXEN bus. Their state is published with the generic I/O device as feedback.

Parameters — motor (function 7)

One set per discovered controller, stored against its node number, so it stays with that controller across restarts.

Parameter	Type	Default	Meaning
InstanceNum	0…62	0	the motor's instance on the MUXEN bus. Unlike most MUXEN devices this defaults to a live number, so a new controller publishes immediately at instance 0
BindToParc	1…3, 254, 255	254	which battery bank drives the power-limitation relay. 254 = decide automatically, 255 = standalone (no bank watched, relay 2 stays open)
NodeId	0…127	35	the controller's node number on the propulsion bus; overwritten with the real one at discovery
CmdRemoteTimeOut	ms	2000	not used by this firmware — the regeneration hold is fixed at 5 s
ProductId, HardwareId, SoftwareId, SoftwareVersion	read-only		see Reference

Changes take effect at the next restart — write with --reboot.

Automatic bank binding

While BindToParc is 254 the gateway picks the bank from the first valid DC bus voltage it reads, writes the result into the parameter and never revisits it:

Measured bus voltage	Bank
43.0 – 60.0 V	1
10.0 – 16.0 V	2
20.0 – 30.0 V	3
anything else	255 — standalone, relay 2 never closes

Parameters — generic I/O (function 17)

The common ones — see Reference — except that EnGenIo has no effect here: the inputs and relay states publish as soon as the device has an instance number below 63.

Routines

Routine	Payload	Effect
1	0001	restore that device's instance number to its default
1	any bit above bit 0	restore its other parameters — erases the bank binding

Timings and thresholds

Motor state published every	500 ms
A controller is declared off after	1.5 s of silence
Regeneration request held for	5 s after the last request
Generic I/O published every	500 ms, and on a change of 50 mV or more

The propulsion side

Bus	CAN 2, 250 kbit/s, fixed by the firmware
Direction	receive only — the gateway never transmits on this bus
Filtering	none: the whole bus is read, controllers recognised by the shape of their frame identifiers
Frames read	shaft speed and temperature; the drive/regeneration mode; DC bus voltage and current; the sign of life
Discovery	the first time a controller reports DC bus voltage and current
Controllers handled at once	15
Motor instance numbers	0…62

Controllers are told apart by the low 6 bits of their node number: two whose node numbers differ by exactly 64 share one configuration slot.

Known limitations

• No fault codes: a controller in fault is published as error, and error is the whole of the fault reporting.
• Direction of rotation is lost — the published speed is a magnitude.
• The sequence counter published with the motor state never advances.
• One of the frame groups received from the controller is read but nothing is taken from it.
• CmdRemoteTimeOut is listed but inert.

Versions

Hardware	Version	Image
CanCan v1	5.2	010010003-app_BellMarine-firmware.srec
CanCan v2	not built	—

Source: workspace/muxen/cancan/app_BellMarine/, product overlay boards/arm/muxen_cancan/010010003.overlay.