MBG(4) | Device Drivers Manual | MBG(4)

# NAME

`mbg` — Meinberg Funkuhren timedelta sensor

# SYNOPSIS

`mbg* at pci?`

# DESCRIPTION

The `mbg` driver provides support for Meinberg Funkuhren radio clocks (time signal station and GPS receivers). `mbg` implements a timedelta sensor and the delta (in nanoseconds) between the received time information and the local time can be accessed through the sysctl(8) interface.

The card type is indicated in the sensor description. Currently, the following cards are supported by `mbg`:

GPS170PCI
  3.3V/5V 6-channel GPS receiver card
PCI32
  5V DCF77 time signal station receiver card
PCI509
  5V DCF77 time signal station receiver card
PCI510
  3.3V/5V DCF77 time signal station receiver card
PCI511
  3.3V/5V DCF77 time signal station receiver card
PEX511
  PCI Express DCF77 time signal station receiver card
PZF180PEX
  PCI Express DCF77 time signal station receiver card

The quality of the timedelta is reported as the sensor status:

UNKNOWN
  No valid time information has been received yet.
OK
  The time information is valid and the timedelta is safe to use for applications like ntpd(8).
WARN
  The time information is still valid, but no new time information has been decoded for twelve hours (four days in the case of a GPS170PCI card) due to a reception or parity error. The timedelta should be used with care.
CRITICAL
  No valid time information has been received for more than twelve hours (or four days in the case of a GPS170PCI card) since the sensor state degraded from OK to WARN. This is an indication that hardware should be checked to see if it is still functional.

A second sensor provides the relative signal quality as a percentage. The status of this sensor is used to report the status of the device itself:

OK
  The clock is synchronized.
WARN
  The device's clock is free running on the local oscillator. For DCF77 receiver cards this is not an error and can happen due to the nature of the signal transmission using longwave radio.
CRITICAL
  Hardware failure, e.g. communication with the device failed.

# SEE ALSO

intro(4), pci(4), ntpd(8), sysctl(8)

# HISTORY

The `mbg` driver first appeared in OpenBSD 4.1.

# AUTHORS

The `mbg` driver was written by Marc Balmer <mbalmer@openbsd.org>.

March 23, 2024 | Debian