Supervises a link to another node.

 A NodeLinkSup subscribes to a remote $Node objekt, and checks
 the arrival of the subscribed value. If a new value hasn't arrived
 whithin the TimeoutTime an alarm message is sent.

 The NodeLinkSup objects are handled by the rt_linksup server process.

 The $Node object on the remote node. Specify the node object
 with volume and path, e.g. 'RemoteVolume:Nodes-ProcNode'.

 Note! If the node is mounted, it is easy to mix up the MountObject with
 the remote $Node object. Be sure to specify the remote $Node object.

 Timout time in seconds.
 If a subscription value has not arrive whithin the timeout time,
 an alarm message is sent.

 Subscription interval in seconds.

 Indicates that the link is up.
 LinkUp is true if the link is up, and false if the link is down.

 The last time the link was established.

 The last time the link was lost.

 Number of link up events.

 Subid for the subscription.

 Specifies whether to enable or disable the supervision.
 Note that blocking is done when Control is FALSE. The
 input signal can be inverted.

 FALSE disables the supervision and TRUE or open input
 enables the supervision.

 Specifies the status of supervised quantity. FALSE
 means normal state and TRUE means alarm state.
 The output signal can for instance be used to activate
 an action sequence at alarm state.

 Specifies the status of supervised quantity. FALSE
 means normal state and TRUE means alarm state.
 The output signal can for instance be used to activate
 an action sequence at alarm state.

 Specifies whether to enable or disable the blocking. No
 messages from the supervision object will be sent away
 as long as the object is blocked. The blocking does not
 influence on the 'act' output of the object.

 FALSE disables the the blocking and TRUE enables the
 blocking. When a supervisory object in alarm position
 is blocked current messages will be cancelled.
 Blocking /deblocking is done by means of the 'Alarm
 Blocking Window' in the operator environment.

 Optional text to describe the object. It is used in the
 picture Alarm Limits which is activated from the
 operator window.

 Specifies whether to enable or disable the action,
 which at alarm state implies DetectText to be sent or
 not. FALSE means that no message will be sent at alarm
 state; TRUE means that DetectText is sent at alarm
 state.

 Alarm message. Optional text which will be written out
 at alarm state if DetectOn is TRUE.

 Return message. Text which will be written in the event
 list at return to normal state.

 Specifies the type of the message (=DetectText ) which
 will be sent at alarm state.
 ALARM -- 64 The message always requires an
             acknowledgement and sent to the alarm

 INFO  -- 32 If the message requires acknowledgement is
             it sent to the info part of the alarm
             window and the event list, otherwise only

 Priorities concerning alarm messages.

  -- 67   A-alarm; highest priority. (=43Hex)
  -- 66   B-alarm  (= 42Hex)
  -- 65   C-alarm  (= 41Hex)
  -- 64   D-alarm ; lowest priority. (=40Hex)

 Bit map. A flag combination may be attached to the
 message:

 1  =   If this flag exists the return message
        ReturnText will be sent to the event lists of

 2  =   If this flag exists the acknowledgement message
        will be sent to the event lists of the out

 4  =   If the out unit has a peep-function this will
        be activated when the message is received.

 8  =   The message is sent to every out unit

 16 =   If the message is of the type INFO it will be
        placed in the event list. If this flag exists
        the message is also placed in the INFO square
        of the alarm window where acknowledgement is to

 Reference to a sound object, that defines the sound at the operator
 place when the alarm is active. If no sound object is supplied, an
 ordinary beep is used. The sound object should be of class Sound
 or SoundSequence

 Optional text supplying more information about the event.
 The more text can for example contain actions to be made when an alarm is detected.

 Recipient for epost and mms alarms.
 The recipient is a user defined in the user database in the
 current system group.
 Recipient can also be a list of users separated by comma, eg
 'dennis, jimmy'. Also symbols defined in the Symbol table in
 the PostConfig object can be used. Symbols should be referenced
 with a $ sign before the symbol name, eg '$on_duty'.

 The users should be defined in the current system group or in a
 subgroup to this, If a subgroup is used, the subgroup should
 be specified in the recipient name, eg 'sms.dennis'.

 Attribute is filled in by the server process to the
 NodeLinkSup object itself.

 Status value. Bit map containing 16 bits where the 8
 least significant bits denote the state and the 8 most
 significant bits the priority.
 The state is a combination of:

    -- 0    Normal state
    -- 1    Alarm state
    -- 2    Unacknowledged alarm
 The priority is one of the priorities EventPriority.

 The following status can exist:
    EventPriority + 1 => Priority + alarm state
    EventPriority + 3 => Priority + unacknowledged alarm
 and alarm state

 Used internal at the event detection.

 Specifies if an alarm state will be detected or not.
 FALSE means that an alarm state will not be detected;
 TRUE means that an alarm state will be detected.

 Specifies if the message has already been sent to the
 out units (or more precisely the message handler) or
 not. TRUE means that the message has been sent.

 Date and time when alarm state was detected.

 Specifies if the object has returned to normal state or
 not. TRUE means that the object has returned to normal
 state.

 Specifies if the return message, ReturnText, has been
 sent to the out units or not. TRUE means that the
 return message has been sent.

 Date and time when the last return to normal was
 detected.

 Date and time when the last acknowledgement of normal
 state was detected.

 Identity of the out unit (operator) which made an
 acknowledgement.

 Indicates an active timer.

 Points to the next element in the timer queue.

 Number of remaining ticks.

 Delay in seconds. Specifies when, since an alarm state
 has occurred, the message will be sent. If the alarm
 state disappears before the time has elapsed no message
 is generated.
 TimerTime >= the executing period of the PLC program.

 Identity of this object is set at load file creation.
 Used by the run time system.

 The operator's authorities to change TimerTime. Not
 implemented.

  0   -- Changes not allowed.
  !=0 -- Changes allowed.

 Specifies a valid interval at changes made by the
 operator on TimerTime.

 TimerMin <= TimerTime <= TimerMax

Contains the system status of the supervised node.
If the link is down, the status is PWR__NETTIMEOUT.