[Nut-upsuser] NUT supporting Modbus TCP

Charles Lepple
2017-06-24T16:25:14Z

On Jun 24, 2017, at 10:57 AM, Sergei Naumov wrote:

> I was wonering if there is a driver that supports communicating with a
Modbus aware device over IP. I have a solar/wind invertor that can broadcast its
state and I would like to monitor the batteries. If they discarge to a certain
voltage or come to a defined state, I would perform a shutdown. All of this
information id provided in Modbus holding registers. This could of course be
done placing a Modbus-to-SNMP gateway but they seem to be somewhat pricey.

There is a GitHub issue tracking the general idea of a NUT MODBUS driver:
https://github.com/networkupstools/nut/issues/50

The skeleton code on the referenced branch uses libmodbus, which as I
understand, can communicate over TCP.

However, since you have a specific device in mind, you might be better served by
creating a new driver based on the phoenixcontact_modbus driver (which also uses
libmodbus): https://github.com/networkupstools/nut/pull/404 and
https://github.com/networkupstools/nut/blob/7bd8971db89eec51fa55bbb75c8a54ca4a46e7dc/drivers/phoenixcontact_modbus.c

Do you have a datasheet or protocol document for this device?