values lead to a higher system load produced by collectd, while higher values
lead to more coarse statistics.
+=item B<Timeout> I<Iterations>
+
+Consider a value list "missing" when no update has been read or received for
+I<Iterations> iterations. By default, I<collectd> considers a value list
+missing when no update has been received for twice the update interval. Since
+this setting uses iterations, the maximum allowed time without update depends
+on the I<Interval> information contained in each value list. This is used in
+the I<Threshold> configuration to dispatch notifications about missing values,
+see L<"THRESHOLD CONFIGURATION"> below.
+
=item B<ReadThreads> I<Num>
Number of threads to start for reading plugins. The default value is B<5>, but
=back
+=head2 Plugin C<modbus>
+
+The B<modbus plugin> connects to a Modbus "slave" via Modbus/TCP and reads
+register values. It supports reading single registers (unsigned 16E<nbsp>bit
+values), large integer values (unsigned 32E<nbsp>bit values) and floating point
+values (two registers interpreted as IEEE floats in big endian notation).
+
+Synopsis:
+
+ <Data "voltage-input-1">
+ RegisterBase 0
+ RegisterType float
+ Type voltage
+ Instance "input-1"
+ </Data>
+
+ <Data "voltage-input-2">
+ RegisterBase 2
+ RegisterType float
+ Type voltage
+ Instance "input-2"
+ </Data>
+
+ <Host "modbus.example.com">
+ Address "192.168.0.42"
+ Port "502"
+ Interval 60
+
+ <Slave 1>
+ Instance "power-supply"
+ Collect "voltage-input-1"
+ Collect "voltage-input-2"
+ </Slave>
+ </Host>
+
+=over 4
+
+=item E<lt>B<Data> I<Name>E<gt> blocks
+
+Data blocks define a mapping between register numbers and the "types" used by
+I<collectd>.
+
+Within E<lt>DataE<nbsp>/E<gt> blocks, the following options are allowed:
+
+=over 4
+
+=item B<RegisterBase> I<Number>
+
+Configures the base register to read from the device. If the option
+B<RegisterType> has been set to B<Uint32> or B<Float>, this and the next
+register will be read (the register number is increased by one).
+
+=item B<RegisterType> B<Uint16>|B<Uint32>|B<Float>
+
+Specifies what kind of data is returned by the device. If the type is B<Uint32>
+or B<Float>, two 16E<nbsp>bit registers will be read and the data is combined
+into one value. Defaults to B<Uint16>.
+
+=item B<Type> I<Type>
+
+Specifies the "type" (data set) to use when dispatching the value to
+I<collectd>. Currently, only data sets with exactly one data source are
+supported.
+
+=item B<Instance> I<Instance>
+
+Sets the type instance to use when dispatching the value to I<collectd>. If
+unset, an empty string (no type instance) is used.
+
+=back
+
+=item E<lt>B<Host> I<Name>E<gt> blocks
+
+Host blocks are used to specify to which hosts to connect and what data to read
+from their "slaves". The string argument I<Name> is used as hostname when
+dispatching the values to I<collectd>.
+
+Within E<lt>HostE<nbsp>/E<gt> blocks, the following options are allowed:
+
+=over 4
+
+=item B<Address> I<Hostname>
+
+Specifies the node name (the actual network address) used to connect to the
+host. This may be an IP address or a hostname. Please note that the used
+I<libmodbus> library only supports IPv4 at the moment.
+
+=item B<Port> I<Service>
+
+Specifies the port used to connect to the host. The port can either be given as
+a number or as a service name. Please note that the I<Service> argument must be
+a string, even if ports are given in their numerical form. Defaults to "502".
+
+=item B<Interval> I<Interval>
+
+Sets the interval (in seconds) in which the values will be collected from this
+host. By default the global B<Interval> setting will be used.
+
+=item E<lt>B<Slave> I<ID>E<gt>
+
+Over each TCP connection, multiple Modbus devices may be reached. The slave ID
+is used to specify which device should be addressed. For each device you want
+to query, one B<Slave> block must be given.
+
+Within E<lt>SlaveE<nbsp>/E<gt> blocks, the following options are allowed:
+
+=over 4
+
+=item B<Instance> I<Instance>
+
+Specify the plugin instance to use when dispatching the values to I<collectd>.
+By default "slave_I<ID>" is used.
+
+=item B<Collect> I<DataName>
+
+Specifies which data to retrieve from the device. I<DataName> must be the same
+string as the I<Name> argument passed to a B<Data> block. You can specify this
+option multiple times to collect more than one value from a slave. At least one
+B<Collect> option is mandatory.
+
+=back
+
+=back
+
+=back
+
=head2 Plugin C<mysql>
The C<mysql plugin> requires B<mysqlclient> to be installed. It connects to
This feature is only available if the I<network> plugin was linked with
I<libgcrypt>.
+=item B<Interface> I<Interface name>
+
+Set the outgoing interface for IP packets. This applies at least
+to IPv6 packets and if possible to IPv4. If this option is not applicable,
+undefined or a non-existent interface name is specified, the default
+behaviour is to let the kernel choose the appropriate interface. Be warned
+that the manual selection of an interface for unicast traffic is only
+necessary in rare cases.
+
=back
=item B<E<lt>Listen> I<Host> [I<Port>]B<E<gt>>
using L<stat(2)>. If the file has been changed, the contents is re-read. While
the file is being read, it is locked using L<fcntl(2)>.
+=item B<Interface> I<Interface name>
+
+Set the incoming interface for IP packets explicitly. This applies at least
+to IPv6 packets and if possible to IPv4. If this option is not applicable,
+undefined or a non-existent interface name is specified, the default
+behaviour is, to let the kernel choose the appropriate interface. Thus incoming
+traffic gets only accepted, if it arrives on the given interface.
+
=back
=item B<TimeToLive> I<1-255>
Also, all values that match a threshold are considered to be relevant or
"interesting". As a consequence collectd will issue a notification if they are
-not received for twice the last timeout of the values. If, for example, some
-hosts sends it's CPU statistics to the server every 60 seconds, a notification
-will be dispatched after about 120 seconds. It may take a little longer because
-the timeout is checked only once each B<Interval> on the server.
+not received for B<Timeout> iterations. The B<Timeout> configuration option is
+explained in section L<"GLOBAL OPTIONS">. If, for example, B<Timeout> is set to
+"2" (the default) and some hosts sends it's CPU statistics to the server every
+60 seconds, a notification will be dispatched after about 120 seconds. It may
+take a little longer because the timeout is checked only once each B<Interval>
+on the server.
When a value comes within range again or is received after it was missing, an
"OKAY-notification" is dispatched.
projects / collectd.git / blobdiff