NERD 2nd thoughts...

[_Ralph]

no, he does not. His NERD is an analog NERD using the 4-pin subconn cable. This is a similar cable to the 5-pin cable used in the DiveCAN, but he does not have a canbus monitor on his unit. There is no room in the sidekick head for the board and battery.
I seem to remember that the NERD2 can be converted from Fischer to Subconn with a cable swap. The Petrels can't be, but I'm pretty sure the NERD and NERD2 can be.

Now what Mike SHOULD do is copy Dive Rite's canister system thingy and start making an option for that. Canister has the OBOE board and a 9v or 18650 battery that powers it and then he could actually start using DiveCAN computers, but we shall see if that ever happens.

I can't say if you are more correct than I or I am you, but from the horses mouth .... but I was talking about the connector (analog) itself, not the system which is what I believe you are talking about (digital) ... unless I'm mixed up again.....



_R

 

[stuartv]

I can't say if you are more correct than I or I am you, but from the horses mouth .... but I was talking about the connector (analog) itself, not the system which is what I believe you are talking about (digital) ... unless I'm mixed up again.....

View attachment 581031

_R

I don't mean to speak for tbone. But, I think where Kakuk says "Can-bus connector", if you read it as "can-bus-style connector", it's correct. And tbone is correct. I think a lot of people call that thing a canbus connector when what they really mean is a canbus-style connector. I.e. that 4-pin wet-mateable connector, that is used by DiveCAN (i.e. canbus) setups as well as non-canbus systems.

 

[tbone1004]

@tbone1004 That seems like SUCH a niche case. I get it. But, certainly for where I am at, the benefit is moot. The benefit of less electronics and batteries is much better for me.

Anyway, it seems like if you were going to have 2 CCRs in the water, you might want to just have a separate NERD for each?

It's a niche case for sure, but it also moves to a digital system which is inherently more reliable than mV transmission over long distances.

I can't say if you are more correct than I or I am you, but from the horses mouth .... but I was talking about the connector (analog) itself, not the system which is what I believe you are talking about (digital) ... unless I'm mixed up again.....

View attachment 581031

_R

That's a misunderstanding from Brian in the quote you attached. Canbus is a digital communication system, in the case of Shearwater, they call their version of it DiveCAN. The cables that they chose to use are 5-pin SubConn cables.
A while ago, Revo wanted to go away from the idiotic Fischer cables for their analog side monitoring. Fischer cables were chosen back in the day and required 7 pins for a few reasons. 4 pins were required for analog, and then for solenoid control. It was a small, relatively waterproof connector, and the best choice at the time. For the last 10 ish years, after Shearwater stopped producing the Predator controller, there really was no reason to continue with use of the Fischer cables for external monitoring, EXCEPT for the fact that for the EXT Petrels and Predators, they didn't need a cable hanging off the end because the Fischer bulkheads were fairly small. The cables are very expensive from the factory, and there are very long lead times to get them made which require them to be made in considerable quantity because they are custom made. The SubConn's however are standard cables that are easy to purchase off-the-shelf and much less expensive than the Fischer cables. Superior in every way, except the Petrel EXT would have to have to get a little bigger to fit the larger bulkhead which is less than ideal.
After Revo had the idea, KISS came out with it, though their marketing material would make it seem like they were the first to do it, but Revo beat them to it by close to a decade. The analog monitors only have 4-pins to prevent them from being used with the actual canbus/DiveCAN monitors which have 5-pins. Why the DiveCAN side has 5-pins I do not know as they only need 4 to operate, but it is what it is.

 

[stuartv]

@tbone1004 So, the NERD2 monitors for JJ, Dive Rite, etc. that are DiveCAN have a 5-pin connector? For some reason, I thought only the controllers had 5 pins and the DiveCAN monitors had 4.

 

[tbone1004]

@tbone1004 So, the NERD2 monitors for JJ, Dive Rite, etc. that are DiveCAN have a 5-pin connector? For some reason, I thought only the controllers had 5 pins and the DiveCAN monitors had 4.

I can't remember what the controllers have, but this is a Nerd2 monitor. I could have sworn they were the same connectors, but it's been a while since I've played with one and can't remember.

 

[ToneNQ]

................. Why the DiveCAN side has 5-pins I do not know as they only need 4 to operate, but it is what it is.

I'll speculate the 5th pin is a pilot connection. The main power, CAN power, CAN hi and CAN low, will be the essential four pins. To make it a wet connection, you need to know when its actually connected. A pilot connection is a common method used in high voltage systems, where all those pins would be live and touching them on a conductive surface lets the smoke out. The pilot circuit (once closed) activates relays that then allows the system to activate. When the connection is opened the pilot drops out and kills the other circuits, and the pins go dead.

 

[telemonster]

Ground pin longest to avoid damaging anything....

 

[ToneNQ]

Have you got a diagram or something? The application is unique to my CANbus experience, happy to be educated.