MosUtils

The MosUtils object provides some useful methods and fields for working with expressions.

Please note that calling setXXXProperty() function of the MosUtils object will immediately put the script module into demo mode, if it is not licensed

Methods

Name	Description
getTagValueState(path)	Returns a ValueState object for the specified tag. The path to the tag is specified as a string, e.g. "Area1.Tank1.Level". Note that using a data trigger to obtain a tag value is more productive than calling this method.
writeTagValueSync(path, value)	Writes a value to the specified tag and returns a ValueState object as a result of the method. The method is blocking, i.e. the execution of the expression code will be paused until the record result is returned. Be careful when using this method!
getExpressionValueState(path)	Returns a ValueState object for the specified expression. The path to the expression is specified as a string, e.g. "Elec.Power".
getDeviceProperty(groupName, path, propertyName)	Returns the value of a property of the device specified in the method arguments, where groupName is the name of the group, path is the path to the device or subdevice, propertyName is the name of the property.
getStoreProperty(name, propertyName)	Returns the value of a property of the store specified in the method arguments, where name is the name of the store and propertyName is the name of the property.
getTagProperty(path, propertyName)	Returns the value of the property specified in propertyName for the tag specified in path.
setDeviceProperty(groupName, path, propertyName, value)	Sets value of the property specified in propertyName for a device where groupName is the group in which the device is located and path is the device name or path to the subdevice. Also see the commitChanges() method.
setStoreProperty(name, propertyName, value)	Sets value of the property specified in propertyName for the store named name. Also see the commitChanges() method.
setTagProperty(path, propertyName, value)	Sets value of the property specified in propertyName for the tag specified by the argument path. Also see the commitChanges() method.
commitChanges()	Commit changes in any properties set by the setXXXProperty functions. This method must necessarily be called after calling any function of the setXXXProperty type.
sleep(millis)	Suspends script execution for the number of specified milliseconds.
log(eventType, message)	Outputs a message to the server log, allows tracing script execution, where eventType is numeric from 1 to 3 (1 - INFO, 2 - WARNING, 3 - ERROR) and message is the message text.

Fields

Name	Description
doNothing	If you return this property as a result of an expression or throw this property as an exception, the state of the expression will remain unchanged.

Examples

The following example demonstrates obtaining the CommunicationEstablished property for a Modbus device.

return MosUtils.getDeviceProperty('', 'MyPLC', 'CommunicationEstablished');

or (if the device is a subdevice and is located in a group):

return MosUtils.getDeviceProperty('MyGroup', 'MyPLC.SubDevice', 'CommunicationEstablished');

In the following example, the expression updates its state only if the difference from the previous value is more than 20. In this example, the expression has a data trigger named radius.

const DELTA = 20;

// Getting the current value of the expression
var prevValue = context.expression.currentState.value;

// Getting the new value
var newValue = context.data['radius'].state.value

if (Math.abs(newValue - prevValue) > DELTA)
  return newValue;

return MosUtils.doNothing;