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clay123 avatar image
clay123 asked

Can I use a long cable run from CCGX to DMC ?

Hi everyone,

I am currently in the process of designing a system and wanted to know if a 120m run for a CAT5e cable from the CCGX to the DMC would be alright?

The reason for this long run is that the system will be situated in the storage room 100m away from the main house. This area currently has unreliable network/internet connection, so the decision was to have the monitoring system hardwired into the main house for ease of system access.

The system consists of a 5kVA Multiplus II, charge controller, CCGX and gel batteries.

Any advise or suggestions would be much appreciated.

Multiplus-IICCGX Color ControlmonitoringDigital Multi Controlrj45 cable
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matthias-nagel avatar image matthias-nagel commented ·
As you may see from the different answers below some discussion went on wether it works or not. It really depends on the communication protocol. For Ethernet it won't work, for VE.Bus it will most likely work. Hence, it all depends on where you plan to plug the Cat 5e into. If you look at the manual of the CCGX, you will find that the CCGX provides several RJ-48 connectors which all use Cat 5e as cable type, but provide different communication protocols. I recommend to update yot your question as this information is crucial for a proper answer.
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Michelle Konzack avatar image
Michelle Konzack answered ·

Ethernet cable can not be longer the 100m under best conditions.


Better buy a set of Media-Converter (FiberOptic Singel Mode to Ethernet) for 20€ from www.aliexpress.com and an appropriated Outdoor FiberOptic cable (e.G. www.fs.com) which can be as long as 20km...

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dennibu avatar image dennibu commented ·

Ich stimme dem zu. Mit Glasfaser haben Sie auch kein Problem mit möglichen Verzögerungen oder Blitzeinschlägen und Überspannungen im Nachhinein.

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matthias-nagel avatar image matthias-nagel dennibu commented ·

That won't work. The CCGX only uses a Cat. 5e cable as the physical layer to communicate with a DMX, but on the media layer it uses VE.Bus not Ethernet. This means the frame format is completely different.

An optical media-converter as the one in the link from Twisted Pair Cat. 5e to Fiber Single Mode only works for Ethernet.

The maximum length is determined by the frame format. Yes, for Ethernet this are 100m, but for VE.Bus that value can be completely different. For more information on VE.Bus see Data communication with Victron Energy products and Interfacing with VE.Bus products – MK2 Protocol.

As I see it, the VE.Bus is a proprietary protocol based on RS485. The maximum length of "vanilla" RS485 is 1200m. However, I do not know whether Victron has added some proprietary modifications which might have changed that value.

Probably, you should simply try it.

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dennibu avatar image dennibu matthias-nagel commented ·

I understood that it is about an Ethernet connection to a DMC D-Link device to connect the GX to the Internet. I also don't know any reason to connect the VE bus over such long distances.

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matthias-nagel avatar image matthias-nagel dennibu commented ·

Maybe you are right. I understood the question in a different way.

I thought that the CCGX and the DMC currently only communicate indirectly via Internet, but that the Internet connection at one side is unreliable. (IMHO, the question does not say anything about which side has the problem.)

Hence, the OP plans to install a direct connection between the CCGX and DMC which does not require Internet access but allows local communication. I had a look at Color Control GX Manual, Sec. 3.1. You can see a RJ-48 connector (i.e. an "Ethernet" connector) which is labelled VE.Bus and connected to a Digital Multi Control (DMC). I assumed that this is what the OP wants to do. In that case 120m should be fine.

However, without more specific and accurate information from the OP we won't figure it out.

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matt1309 avatar image
matt1309 answered ·

Hi @Clay123

Not a concrete answer but just sharing something that might help. I've not used a DMC before so not sure what type of connection it uses. If the connection protocol is TCP/IP, then 100m tends to be the limit of what most cables note. You may get away with it with high quality shielded cable but can't imagine it's guarantied.

If it's Ve.CAN protocol which I think is just built on normal CAN bus then I've seen comments on here noting that 200m is fine as long as termination resistors are installed.

And for longer runs using high quality shielded cable is recommended. I'll share some old posts I've seen regarding Ve.CAN communication:

Maximum length for VE. Can - Victron Community (victronenergy.com)


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matthias-nagel avatar image matthias-nagel commented ·
If the connection protocol is TCP/IP, then 100m tends to be the limit of what most cables note. You may get away with it with high quality shielded cable but can't imagine it's guarantied.

The limiting factor is not electromagnatic interference, and hence even optimtal shielding won't help you to overcome the 100m limit. The 100m-limit is dictated by the Ethernet frame format (56bit of preamble), the collision detection algorithm CSMA/CD, the clockrate (125 MBd for Fast Ethernet) and the speed of light.

In short: The sender "allocates" the wire by sending out a 56bit 0/1 meander. One must ensure that the first bit reaches the receiver, before the sender has tranmitted the last (i.e. 56th) bit of that meander. Given the clock rate one can calculate the time which the sender requires to sent out all 56 bits, and how far the first bit has been travelling during that time period. You end up with something about 102m. No shielding will change that fact.

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