About the Book

Document Scope

This document will acquaint you with the system functions and variables offered within the Modicon M241 Logic Controller. The M241 PLCSystem library contains functions and variables to get information from and send commands to the controller system.

This document describes the data type functions and variables of the M241 PLCSystem library.

The following knowledge is required:

Basic information on the functionality, structure, and configuration of the M241 Logic Controller.
Programming in the FBD, LD, ST, IL, or CFC language.
System variables (global variables).

Validity Note

This document has been updated for the release of EcoStruxure™ Machine Expert V2.2.

The characteristics that are described in the present document, as well as those described in the documents included in the Related Documents section below, can be found online. To access the information online, go to the Schneider Electric home page www.se.com/ww/en/download/.

The characteristics that are described in the present document should be the same as those characteristics that appear online. In line with our policy of constant improvement, we may revise content over time to improve clarity and accuracy. If you see a difference between the document and online information, use the online information as your reference.

Title of Documentation	Reference Number
EcoStruxure Machine Expert Programming Guide	EIO0000002854 (ENG) EIO0000002855 (FRE) EIO0000002856 (GER) EIO0000002858 (SPA) EIO0000002857 (ITA) EIO0000002859 (CHS)
Modicon M241 Logic Controller Hardware Guide	EIO0000003083 (ENG) EIO0000003084 (FRE) EIO0000003085 (GER) EIO0000003086 (SPA) EIO0000003087 (ITA) EIO0000003088 (CHS)
Modicon M241 Logic Controller Programming Guide	EIO0000003059 (ENG) EIO0000003060 (FRE) EIO0000003061 (GER) EIO0000003062 (SPA) EIO0000003063 (ITA) EIO0000003064 (CHS)

Product Related Information

WARNING
	LOSS OF CONTROL Perform a Failure Mode and Effects Analysis (FMEA), or equivalent risk analysis, of your application, and apply preventive and detective controls before implementation. Provide a fallback state for undesired control events or sequences. Provide separate or redundant control paths wherever required. Supply appropriate parameters, particularly for limits. Review the implications of transmission delays and take actions to mitigate them. Review the implications of communication link interruptions and take actions to mitigate them. Provide independent paths for control functions (for example, emergency stop, over-limit conditions, and error conditions) according to your risk assessment, and applicable codes and regulations. Apply local accident prevention and safety regulations and guidelines.¹ Test each implementation of a system for proper operation before placing it into service. Failure to follow these instructions can result in death, serious injury, or equipment damage.

WARNING

LOSS OF CONTROL

Perform a Failure Mode and Effects Analysis (FMEA), or equivalent risk analysis, of your application, and apply preventive and detective controls before implementation.
Provide a fallback state for undesired control events or sequences.
Provide separate or redundant control paths wherever required.
Supply appropriate parameters, particularly for limits.
Review the implications of transmission delays and take actions to mitigate them.
Review the implications of communication link interruptions and take actions to mitigate them.
Provide independent paths for control functions (for example, emergency stop, over-limit conditions, and error conditions) according to your risk assessment, and applicable codes and regulations.
Apply local accident prevention and safety regulations and guidelines.¹
Test each implementation of a system for proper operation before placing it into service.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

¹ For additional information, refer to NEMA ICS 1.1 (latest edition), Safety Guidelines for the Application, Installation, and Maintenance of Solid State Control and to NEMA ICS 7.1 (latest edition), Safety Standards for Construction and Guide for Selection, Installation and Operation of Adjustable-Speed Drive Systems or their equivalent governing your particular location.

WARNING
	UNINTENDED EQUIPMENT OPERATION Only use software approved by Schneider Electric for use with this equipment. Update your application program every time you change the physical hardware configuration. Failure to follow these instructions can result in death, serious injury, or equipment damage.