Mediator

Broad Concept

Most mover actions can be represented as a combination of a Station, Position Trigger or Zone and a mover. However there are some system-level concepts that require knowledge of all of the stations, movers, zones, etc. The Mediator fulfills this role.

By using the system level Mediator, functionality such as next and previous movers can be realized and tasks that need to be called once for the entire system can be managed such as locating Mover 1 at startup.

Finally, the Mediator handles calling the necessary .Cyclic() methods on all objects within the system, simplifying code needed to be managed by the end user.

In this code the Mediator object is instantiated as the variable System().

Configuration

Code already exists to make the mediator aware of all Movers, MoverLists, PositionTriggers, Stations, Zones and Tracks. It is executed at the appropriate states in the MAIN program. However, the mediator must be made aware of the number of each object. This is accomplished in the global variable list GVL.

Update the count of each object according to the needs of the system in this list. It's recommended to oversize these arrays so that during runtime debugging additional stations, zones or position triggers can be added without the need to stop and recompile the PLC program.

Methods

Cyclic

Cyclic()

Required to be called once per scan. The Mediator will then call all necessary .Cyclic() methods for the objects that are registered to it.

PartMotorModules48vReady

PartMotorModules48vReady( PartTcIo : I_TcIoXtsXpuPart )

Returns true if all motor modules on the part have 48v available.

This method is used internally during enable and is not needed in most use cases. It is provided for the infrequent application where a portion of the XTS track has 48V power removed, often in relation to a nearby guard door being opened. This kind of application has significant safety considerations that need to be studied via a risk assessment, which is outside the scope of this documentation.

PartMotorModulesEnabled

PartMotorModulesEnabled( PartTcIo : I_TcIoXtsXpuPart )

Returns true if all motor modules on the part are ready.

Ready consists of 24V and 48V being present, and the motor module has completed its internal power up sequence after receiving 48V.

PartMotorModules48vReady should be checked prior to issuing enable commands and when the enable commands compete, this value will become true.

This method is used internally during enable and is not needed in most use cases. It is provided for the infrequent application where a portion of the XTS track has 48V power removed, often in relation to a nearby guard door being opened.This kind of application has significant safety considerations that need to be studied via a risk assessment, which is outside the scope of this documentation.

// declaration
PartToTest : I_TcIoXtsXpuPart;

// code
// get a part from the XTS environment
PartToTest := XTS.System.Environment.XpuTcIo(1).PartTcIo(1)
// act on the state of the part's ready status
if (XTS.System.PartMotorModulesReady(PartToTest)) THEN
    // Alert operator system is ready
END_IF

ResetStatistics

ResetStatistics()

Some objects provide statistics that can be used to monitor throughput, utilization, mover velocites and other values and their averages. This method resets all of the statistics collected back to zero after which they begin monitor their values again.

MuteAllPositionTriggers

MuteAllPositionTriggers()

Sends the .MuteCurrent() command to all position triggers.

Positions triggers should be evaluated on the same scan as when their .MoverPassedPosition flag has been raised to ensure no mover is missed at a position trigger. However, it is not uncommon for position triggers to only be monitored when the XTS is in the RUN mode, but movers may pass these triggers during the RECOVERY mode. In this case the .MoverPassedPosition flag indicates a mover has passed this position, but may not have been relevant to the code in RUN and could no longer be near the position trigger. To make it easy to clear out the non-relevant triggers this method can be called.

Note

This method is already called in RECOVERY_ONESHOT and the transition to run RUN. If this behavior is not desired it can be modified in MAIN.

Other Methods

The following methods are used internally by the Mediator and are not intended for direct access.

• AddMover
• AddMoverList
• AddPositionTrigger
• AddStation
• AddTrack
• AddZone
• EnableGroup

Properties

AllMotorModules48vReady

BOOL

Returns true if all modules in the system are reporting 48v is on and ready.

See PartMotorModules48vReady for use cases and sequence notes.

AllMotorModulesEnabled

BOOL

Returns true if all motor modules have 48v and have completed the internal enable sequence.

See PartMotorModulesEnabled for use cases and sequence notes.

CompleteMoverList

MoverList

Returns a list of all movers within the system.

System.CompleteMoverList.HaltAll();

Environment

I_TcIoXtsEnvironment

Returns the environment of this XTS system. The Mediator initializes FB_TcIoXtsEnvironment and the info server and provides this as a convenience.

This property should always be used after checking if the environment is initialized.

IF (System.EnvironmentIsReady) THEN
    System.Environment.GetXpuCount(TRUE);
END_IF;

EnvironmentIsReady

BOOL

Returns the status of the initialization of FB_TcIoXtsEnvironment.

The Mediator initializes FB_TcIoXtsEnvironment and the info server and returns this as a convenience status.

IF (System.EnvironmentIsReady) THEN
    // examine an Environment parameter or call a method
END_IF;

GroupEnabled

BOOL

Returns the status of the collision avoidance group enabled state. This is the response from the method .EnableGroup();

GroupError

BOOL

If an error is generated by the collision avoidance group it is GroupError is true.

InfoServer

I_TcIoXtsInfoServer

Returns the info server of the XTS system.

The Mediator initializes FB_TcIoXtsEnvironment followed by FB_TcIoXtsInfoServer and provides the info server as a convenience.

This property should always be used after checking if the environment is initialized and the info server is initialized.

IF (System.EnvironmentIsReady) THEN
    InfoStationCount := System.InfoServer.GetInfoStationCount();
END_IF;

InfoServerIsReady

BOOL Returns the status of the initialization of FB_TcIoXtsInfoServer.

The Mediator initializes FB_TcIoXtsEnvironment followed by FB_TcIoXtsInfoServer and provides the info server as a convenience status.

IF (System.InfoServerIsReady) THEN
    // examine an InfoServer object
END_IF;

Mover1DetectionComplete

BOOL

Returns the status of the mover 1 detection. This is the response from the method .DetectMover1();

XPU

­I_TcIoXtsProcessingUnit

Returns the XTS Processing Unit of the XTS system.

The Mediator initializes FB_TcIoXtsEnvironment and then provides this interface to the XPU as a convenience.

This property should always be used after checking if the environment is initialized and the info server is initialized.

IF (System.EnvironmentIsReady) THEN
    Mode := System.XPU.GetOperationMode();
END_IF;