apc_modbus: "upsdrvctl start" fails

[moritzkraemer]

Hi,

i compiled nut with the modbus support (https://github.com/networkupstools/nut/wiki/APC-UPS-with-Modbus-protocol) and copied the apc_modbus driver into "/lib/nut/" but "upsdrvctl start" now fails:

Network UPS Tools - UPS driver controller 2.8.1
Network UPS Tools 2.8.2.1725-1725-gc641cff57 (development iteration after 2.8.2) - NUT APC Modbus driver with USB support 0.11
modbus_connect: unable to connect: No such device
upsnotify: failed to notify about state NOTIFY_STATE_STOPPING: no notification tech defined, will not spam more about it
Driver failed to start (exit status=1)

my ups.conf:

[UPS1]
        driver = apc_modbus
        port = auto
        serial = ASxxxxxxxxxx

[jimklimov]

Can you please run with more debug, and ideally the driver program itself?

What system do you run it on?

There may be a problem of unexpected APC vendorid/productid values on your device, that the driver code does not know about; try passing those as driver args.

I wonder if it's a duplicate of #2289 et al, or a separate issue?..

[moritzkraemer]

./apc_modbus -DDDDD -s apc -x vendorid=051D -x productid=0003 -x port=auto

results in:

Network UPS Tools 2.8.2.1725-1725-gc641cff57 (development iteration after 2.8.2) - NUT APC Modbus driver with USB support 0.11
   0.000124     [D5] send_to_all: SETINFO driver.version.usb "libusb-1.0.27 (API: 0x100010a)"
   0.000143     [D1] Using USB implementation: libusb-1.0.27 (API: 0x100010a)
   0.000157     [D1] This build of the driver is USB-capable; also Serial and TCP Modbus RTU are supported
   0.000206     [D3] main_arg: var='vendorid' val='051D'
   0.000249     [D5] send_to_all: SETINFO driver.parameter.vendorid "051D"
   0.000268     [D3] main_arg: var='productid' val='0003'
   0.000286     [D5] send_to_all: SETINFO driver.parameter.productid "0003"
   0.000300     [D3] main_arg: var='port' val='auto'
   0.000317     [D5] send_to_all: SETINFO driver.parameter.port "auto"
   0.000329     [D1] Network UPS Tools version 2.8.2.1725-1725-gc641cff57 (development iteration after 2.8.2) built with gcc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0 and configured with flags: --with-drivers=apc_modbus --with-usb --with-modbus --with-modbus-includes=-I/usr/local/ups/include/modbus --with-modbus-libs='-L/usr/local/ups/lib -lmodbus'
   0.000363     [D1] debug level is '5'
   0.000379     [D5] send_to_all: SETINFO driver.debug "5"
   0.000395     [D5] send_to_all: SETFLAGS driver.debug RW NUMBER
   0.000666     [D1] Can not become_user(nobody): not root initially, remaining UID=1000 GID=1000
   0.000703     [D1] Signalling UPS [apc]: driver.exit (quietly, no fuss if no driver is running or responding)
   0.000730     Can't open /var/state/ups/apc_modbus-apc: No such file or directory
   0.000745     [D1] Request for other driver to exit returned code -1
   0.000760     [D1] Socket dialog with the other driver instance (may be absent) failed: No such file or directory
   0.000777     [D5] send_to_all: SETINFO device.type "ups"
   0.000793     [D5] send_to_all: SETINFO driver.state "init.device"
   0.009415     modbus_connect: unable to connect: No such device
   0.009445     [D5] send_to_all: SETINFO driver.state "cleanup.exit"
   0.009460     upsnotify: failed to notify about state NOTIFY_STATE_STOPPING: no notification tech defined, will not spam more about it
   0.009478     [D1] On systems without service units, consider `export NUT_QUIET_INIT_UPSNOTIFY=true```

[jimklimov]

Strange, it does not even seem to try finding the device. Also it tries to run as nobody (by default, as you did not configure any --with-user explicitly) but you seem to have started as someone else. Maybe the resulting account does not have permissions to the USB device FS node.

Try running via sudo or similar, to start as root, and pass -u root or -x user=root to rule put that devfs permissions are a problem.

Also, just in case - are you sure your model/firmware version should talk modbus and not USB HID or some other protocol?

[moritzkraemer]

sudo and all the other options give the same result

the output of sudo nut-scanner -U:

[nutdev1]
        driver = "apc_modbus"
        port = "auto"
        vendorid = "051D"
        productid = "0003"
        product = "Smart-UPS_1500 FW:UPS 06.0 / ID=1027"
        serial = "ASxxxxxxxxxxx"
        vendor = "American Power Conversion"
        bus = "001"
        device = "002"
        busport = "004"
        ###NOTMATCHED-YET###bcdDevice = "0001"

usb-hid driver works but doesnt give all the values

[moritzkraemer]

So i've just been able to update the firmware on the device and now the output is different:

sudo ./apc_modbus -DDDDD -s apc -x vendorid=051D -x productid=0003 -x port=auto -x user=root

returns:

   0.000000     [D5] send_to_all: SETINFO driver.state "init.starting"
Network UPS Tools 2.8.2.1725-1725-gc641cff57 (development iteration after 2.8.2) - NUT APC Modbus driver with USB support 0.11
   0.000105     [D5] send_to_all: SETINFO driver.version.usb "libusb-1.0.27 (API: 0x100010a)"
   0.000119     [D1] Using USB implementation: libusb-1.0.27 (API: 0x100010a)
   0.000131     [D1] This build of the driver is USB-capable; also Serial and TCP Modbus RTU are supported
   0.000153     [D3] main_arg: var='vendorid' val='051D'
   0.000169     [D5] send_to_all: SETINFO driver.parameter.vendorid "051D"
   0.000201     [D3] main_arg: var='productid' val='0003'
   0.000215     [D5] send_to_all: SETINFO driver.parameter.productid "0003"
   0.000228     [D3] main_arg: var='port' val='auto'
   0.000242     [D5] send_to_all: SETINFO driver.parameter.port "auto"
   0.000270     [D3] main_arg: var='user' val='root'
   0.000283     [D1] testval_reloadable: setting 'user' exists and differs: new value 'root' vs. 'nobody'
   0.000295     [D1] Overriding previously specified user 'nobody' with 'root' specified for driver section
   0.000305     [D1] Network UPS Tools version 2.8.2.1725-1725-gc641cff57 (development iteration after 2.8.2) built with gcc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0 and configured with flags: --with-drivers=apc_modbus --with-usb --with-modbus --with-modbus-includes=-I/usr/local/ups/include/modbus --with-modbus-libs='-L/usr/local/ups/lib -lmodbus'
   0.000332     [D1] debug level is '5'
   0.000345     [D5] send_to_all: SETINFO driver.debug "5"
   0.000358     [D5] send_to_all: SETFLAGS driver.debug RW NUMBER
   0.001215     [D1] Succeeded to become_user(root): now UID=0 GID=0
   0.001247     [D1] Signalling UPS [apc]: driver.exit (quietly, no fuss if no driver is running or responding)
   0.001284     Can't open /var/state/ups/apc_modbus-apc: No such file or directory
   0.001295     [D1] Request for other driver to exit returned code -1
   0.001305     [D1] Socket dialog with the other driver instance (may be absent) failed: No such file or directory
   0.001317     [D5] send_to_all: SETINFO device.type "ups"
   0.001328     [D5] send_to_all: SETINFO driver.state "init.device"
   0.105070     [D3] match_function_regex: matching a device...
   0.105179     [D2] match_function_regex: failed match of VendorID: 8087
   0.105203     [D1] _apc_modbus_usb_callback: Failed to match!: Success
   0.125373     [D3] match_function_regex: matching a device...
   0.125473     [D2] _apc_modbus_usb_callback: Matched American Power Conversion  Smart-UPS_1500 FW:UPS 18.0 / ID=1027 (USB VID/PID 051d:0003)
   0.125546     [D2] _apc_modbus_usb_callback: Checking American Power Conversion  Smart-UPS_1500 FW:UPS 18.0 / ID=1027 (USB VID/PID 051d:0003) report descriptors
   0.126014     [D1] _apc_modbus_usb_callback: Found report ids RX=0x90 TX=0x89
   0.126057     [D5] send_to_all: SETINFO ups.vendorid "051d"
   0.126091     [D5] send_to_all: SETINFO ups.productid "0003"
   0.141736     [D5] send_to_all: SETINFO driver.state "init.quiet"
   0.141809     [D5] send_to_all: SETINFO driver.version "2.8.2.1725-1725-gc641cff57"
   0.141843     [D5] send_to_all: SETINFO driver.version.internal "0.11"
   0.141880     [D5] send_to_all: SETINFO driver.name "apc_modbus"
   0.141931     [D5] send_to_all: SETINFO driver.state "init.info"
*** bit out of range 0 - FD_SETSIZE on fd_set ***: terminated
Aborted

[jimklimov]

Hm, so it seems the driver indeed is not compatible with all firmwares out there, to the point of not even detecting them as a device (or the firmware not representing itself as a device visible to the OS)?

From my reading, your FW version changed quite significantly - from 06.0 to 18.0, right?

*** bit out of range 0 - FD_SETSIZE on fd_set ***: terminated
Aborted

Now this issue is unfortunately known with some devices, although not fully understood yet, tracked in #2289 / #2609 - and after the firmware update, your case seems to have become a duplicate of those.

FWIW, there is a fair amount of log notes in those issues (especially the latter) jotted down while I was reading through code and log dumps. One question from those still stands:

Just in case, do your devices also present as a serial port (e.g. /dev/ttyUSB0)? That might work differently as a serial Modbus RTU.
An alternative experiment could be to hack around apc_modbus.c and use the second connection method from the library (also usb, but for paths).

[jimklimov]

Also, which computer is this build of NUT running on - a Raspberry, or some other platform? (Trying to check if this is something specific to ARM versions of Linux distributions/headers, etc.)

[moritzkraemer]

The FW changed fron 06.0 to 18.0, right correct.

The Device does not appear as a serial device as far as i can tell.

NUT is running on Ubuntu 24.04.1 LTS (GNU/Linux 6.8.0-51-generic x86_64).
I would be able to test some different distros any specific you would suggest to try?

[jimklimov]

Well, it is good to know that the problem is not ARM-specific, at least -- thanks!

I don't think switching distros would help at the moment, the problem has to be between new codebases in apc_modbus driver and the fork of libmodbus, as explored in those issues...