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What you need
The gateway
One CanCan running the J1939 firmware, product ID 010010034 — either generation. See the note on CanCan v2 below before choosing.
On the genset side
| A genset with a J1939 output | of one of the two recognised families: Fischer Panda, or Cummins Onan. See J1939 gateway (010010034) — Overview |
| A J1939 bus in working order | the genset must claim a source address and answer address-claim requests. A genset that does not appear on its own bus does not appear on the boat |
The genset installation must be commissioned and working before the gateway is fitted. The gateway reads a bus; it does not set up a genset.
Wiring
| Connector | Goes to | Speed |
|---|---|---|
| CAN 1 | the boat's MUXEN bus | 500 kbit/s |
| CAN 2 | the genset's J1939 bus | 250 kbit/s — fixed by the firmware, it cannot be changed by configuration |
250 kbit/s is the usual J1939 rate and this firmware assumes it unconditionally: it sets that speed on the second bus at every start, whatever the box's own settings say. A genset configured for another rate will not be decoded at all.
Both are ordinary 120 Ω CAN buses: two wires and a common ground, one 120 Ω termination at each physical end of each bus and nowhere else. The gateway is terminated only if it happens to be at the end of a segment.
The two buses stay electrically separate. Nothing crosses from the MUXEN bus to the J1939 bus except the genset commands this firmware deliberately translates.
The gateway's own address on the J1939 bus
The gateway joins the J1939 bus as a node of its own and claims source address 0x53 (83) by default, moving elsewhere if that address is taken. Nothing needs to be reserved for it, but a bus where another node insists on 83 and refuses to arbitrate is worth a look.
The box's own inputs and outputs
Two relays, two dry-contact inputs, two analog inputs — available here as on every CanCan, and independent of the genset function. They are off by default; see Reference.
On this firmware the two relays can also follow a MUXEN equation (Relay1Eqn, Relay2Eqn) instead of being driven only from the bus. See Reference — J1939 gateway.