SOCOMEC_JBUS(8)
===============

NAME
----

socomec_jbus - Driver for Socomec JBUS UPS with
RS-232 serial Modbus connection.

SYNOPSIS
--------

*socomec_jbus* -h

*socomec_jbus* -a 'DEVICE_NAME' ['OPTIONS']

NOTE: This man page only documents the hardware-specific features of the
socomec_jbus driver.  For information about the core driver, see
linkman:nutupsdrv[8].

SUPPORTED HARDWARE
------------------

This driver supports Socomec JBUS series, online (double conversion)
UPS with the following characteristics.

1. Single phase and 3-phase UPS

2. Connection: RS-232

These are typically provided with a Netvision WEB/SNMP management
card / external box that would be better served by the linkman:snmp-ups[8]
driver. In case netvision isn't available, you can hook up the UPS directly
via the serial port and use this driver.

Currently, it has only been tested on the following model.

* DIGYS 3/3 15kVA

In theory, any Socomec JBUS model should work. It should be discovered
as ``Unknown Socomec JBUS'' with a numeric id that I'll need to add it
to the list of supported UPSs.

Sadly, Socomec document only mentions DELPHYS MX and DELPHYS MX elite and
I have the id of my own DIGYS, so chances are, your model will not be
recognized but will probably mostly work. Please report successful
or unsuccessful results to the bug tracker or the mailing list.
Make sure to include the full model number of your UPS manually
in your report.

socomec_jbus uses the libmodbus project, for Modbus implementation.

CABLING
-------

The UPS has an RS-232 port which should be connected with a NULL-modem
cable to a PC serial port. The UPS tested has a female DB9 connector,
so if you construct the cable yourself, make note of the connector type to
avoid using gender changers.

RS-232 is supported on all operating systems, either via a built-in serial
port on your computer, or by using an external USB-to-RS-232 converter. If
you plan to use an USB-to-RS-232 converter, make sure it's supported by your
operating system.


INSTALLATION
------------

This driver should be built by default if libmodbus and development headers
are available. You can force the `configure` script to build it with the
following arguments:

    :; ./configure --with-serial=yes --with-modbus=yes

You also need to give proper (R/W) permissions on the local serial device
file to allow the NUT driver run-time user to access it. This may need
additional setup for start-up scripting, udev or upower rules, to apply
the rights on every boot -- especially if your device nodes are tracked
by a virtual filesystem.

For example, a USB-to-serial converter can be identified as `/dev/ttyACM0`
or `/dev/ttyUSB0` on Linux, or `/dev/ttyU0` on FreeBSD (note the capital "U").
A built-in serial port can be identified as `/dev/ttyS0` on Linux or one of
`/dev/cua*` names on FreeBSD.

INSTANT COMMANDS
----------------

This driver does not (yet?) support sending commands to the UPS.

VARIABLES
---------

This driver does not support writable runtime variables (see linkman:upsrw[8]):
for the same reasons.
Both should be trivial to implement, but since I've already found one or two
inconsistencies in the documentation, I'm withholding from trying them.

KNOWN ISSUES AND BUGS
---------------------

Well, it is an alpha release at best, but so far appears to report the UPS
status reliably. Mostly based on the work of Yifeng Li <tomli@tomli.me> on
the linkman:huawei-ups2000[8] in that very same source tree.

Read failure on some JBUS addresses
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The driver polls all documented JBUS addresses, and it is quite possible
that your UPS model does not support one of them (e.g. the Digys does not
support address '0x1020' which should provide the current UPS status).
This should be logged with `LOG_ERR` from `modbus_read_input_registers()`
along with the address that produced the error.

Data stale
~~~~~~~~~~~

Under certain circumstances, some registers can return invalid values
and trigger a "data stale" error. Once a data stale error has occurred,
you should see error messages similar to the example below in the system
log.

    socomec_jbus: modbus_read_input_registers(addr:XXXX, count:Z):
        Illegal data address
    upsd: Data for UPS [socomec] is stale - check driver
    upsd: UPS [socomec] data is no longer stale

So far all known problems have been fixed by the author, but an unknown one
cannot be ruled out. If you have encountered "data stale" problems during
normal uses, please file a bug report with full logs attached.

Before troubleshooting or reporting a problem, it's important to check
your *dmesg* log for USB connect and disconnect events to avoid wasting
time on the NUT driver when the actual problem is USB. For example, if
someone yanks the cable out of the USB port, or if a new USB device is
plugged into a USB host/hub that is struggling to power its ports
(common on single-board computers like Raspberry Pi), or if you have
flaky cabling or EMI noise, the serial converter can get disconnected
from USB, at least briefly. This creates a permanent data stale, the driver
must be restarted (plugging the USB back won't fix it, since the driver
is still using the nonexistent serial device). These USB problems usually
have nothing to do with NUT. If it's the case, you should solve the
underlying USB problem -- check the cable, check the converter, try a
powered USB hub, try a full-speed USB isolator, etc.

AUTHOR
------

Thanos Chatziathanassiou <tchatzi@arx.net>

SEE ALSO
--------

The core driver:
~~~~~~~~~~~~~~~~

linkman:nutupsdrv[8]

Internet resources:
~~~~~~~~~~~~~~~~~~~

* The NUT (Network UPS Tools) home page: https://www.networkupstools.org/
* Socomec JBUS/Modbus Reference Guide:
  https://www.socomec.com/files/live/sites/systemsite/files/GB-JBUS-MODBUS-for-Delphys-MP-and-Delphys-MX-operating-manual.pdf
* libmodbus home page: http://libmodbus.org
