Introduction into IEC 61131- 4 User Guidelines

Scope

This Technical report (TR) IEC 61131-4 is to introduce the end-users of PLC to the IEC 61131 standard, and to assist the end-users in selection and specifying their equipment requirements according to the IEC61131standard.

This TR has as its main audience the PLC users. As depicted in Figure 1 the users consist of System integrators and End-users. The Vendor of PLC is required by the IEC 61131 standard to furnish appropriate product information to the user. The user needs to supply applications requirement and specifications to the vendor in order to receive suitable products and services from the vendor. The object of this TR then is to assist in this communication, especially from the end-user's perspective. Accordingly, this TR does not detail all the requirements of each and every part of IEC 61131 standard, such as conformance tests. The user should refer to the individual parts of the standard when needed.

The International Standard IEC61131 applies to programmable controllers (PLC) and their associated peripherals. PLCs and their associated peripherals are considered as components of a control system. Therefore, this standard does not deal with the automated system in which the programmable controller system is but one component. However, when applying this User guidelines an overall system architecture evaluation is recommended.

Since PLCs are component devices, overall automated system safety is beyond the scope of this standard.