The NEMA 2000 hardware
is based on DeviceNet.
DeviceNet was developed by Allen-Bradley (Rockwell Automation) based on the CAN and is now overseen by ODVA.
DeviceNet is used at industrial sites largely for motor
controls, sensors, etc.
It is not uncommon for connections to devices to be done with terminal strips althought the connectors are also seen. Mixing does not have an impact.
What seems to be important is that wire is consistent and that terminators at the end of the backbones are in place. Not exceeding the overall specified length of cabling in the system is also important. Since the network can have several branches, layout of the network can impact the overall length and where the terminators should be placed.
With DeviceNet one of the issues was the speed at which the network ran as longer cable length could be supported with slower speeds. Making sure the cable length would support the desired speed and that all devices are configured to run at the desired speed can be an issue. With NMEA 2000
this is not an issue.
On a sailboat with a wind
instrument the logical placement of one of the terminators would be at the wind
instrument at the top of the mast
due to the
length of the run up to the top of the mast
Maretron NMEA 2000
cabling can be purchased for under $2.00/foot and Micro Fittings for around $15 a piece.
Currently I am in the process of installing a NMEA
2000 network on Crazy Fish
using B&G components and a mixture of B&G and Maretron cabling and connectors. My one issue is the run up the mast. Current
cabling originally installed for a Datamarine consists of a shielded cable with 6 additional wires. I am going to splice the NMEA
2000 cabling into this at each end, attached the B&G wind instrument and then scope
it to see how clean the signals are. If not good I will need to step the mast and run new cable. Being based in San Diego
its fairly rare to step the mast.