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guy-immega avatar image
guy-immega asked

BMV-700 Streaming SOC via VE.Direct

I will use BMV-700 in remote location to monitor battery SOC over the Internet. To do this, I want to read VE.Direct output (RS-232) and convert it to a DC voltage 0-10V, connected to a remote monitoring system (10V = 100% SOC). There are many industrial RS-232 to DC converter modules available (e.g. LTS61 from Laurels).

My problem is that: "On power up, a VE.Direct interface will always be in Text-mode, and continuously transmits all runtime fields.” Is it possible to force the BMV-700 VE.Direct Text-mode to transmit SOC readings only? (I will not use HEX-messages.)

BMV Battery Monitor
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wkirby answered ·

The BMV-700 is not transmitting in RS-232. It is transmitting in 3.3V TTL serial.

Then, it transmits all fields as you know. It is not possible to select individual fields to transmit from the device. You will need to use an Arduino routine or something like that to process and then forward only the information that you need.

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guy-immega avatar image guy-immega commented ·

Victron sells a cable that converts VE.Direct to RS-232, so that isn't a problem.

Where can I find documentation of the entire data stream from the BMV-700? The VE.Direct protocol document says only: <Newline><Field-Label><Tab><Field-Value>. The <Field-Label> is "An arbitrary length label that identifies the field." I need to know the precise length of all data which is not an ASCII <Field-Value> for SOC, so these characters can be ignored.

I am amazed that Victron makes no provision for remote monitoring of the BMV-700 SOC over the Internet. Has no user ever attempted this?

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wkirby avatar image wkirby ♦♦ guy-immega commented ·

Documentation can be found here towards the bottom of the list are various documents relating to VE.Direct
https://www.victronenergy.com/support-and-downloads/technical-information

Victron has made provision for remote monitoring of it products on the internet. It is called VRM. A gateway device is required. There is an open source pathway for the gateway or GX device which can be run on RaspberryPi or BeagleBone boards.
Links in this blog post: https://www.victronenergy.com/blog/2017/09/06/raspberry-pi-running-victrons-venus-firmware/

Just to clarify again, the interface on the BMV is NOT RS-232. It is 3.3V TTL Serial.
Do not link an RS-232 interface to this device, this signal levels are too high.

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guy-immega answered ·

Re: BMV-700 SOC on VE.Direct: I am still hoping for a reply. The VE.Direct to RS232 interface is Victron part number ASS030520500.

Has anyone documented the streaming output of the BMV-700, repeated every second? Where can I find the detailed format of this data stream?

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Vance Mitchell avatar image Vance Mitchell commented ·

Victron open source

This should have most of the information you are after.

Have you looked at Victron Venus on raspberry Pi?
There are a few options to achieve what you want, personally I use a Raspberry Pi to log and display all my data online via VRM.

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