IEC 62541-4:2020 RLV contains both the official IEC International Standard and its Redline version. The Redline version is not an official document, it is available in English only and provides you with a quick and easy way to compare all the changes between the official IEC Standard and its previous edition.
a) Added ability to resend all data of monitored items in a Subscription using the ResendData Method.
b) Added support for durable Subscriptions (lifetime of hours or days).
c) Added Register2 and FindServersOnNetwork Services to support network-wide discovery using capability filters.
d) Removed definition of software certificates. Will be defined in a future edition.
e) Extended and partially revised the redundancy definition. Added sub-range definitions for ServiceLevel and added more terms for redundancy.
f) Added a section on how to use Authorization Services to request user access tokens.
g) Added JSON Web Tokens (JWTs) as a new user token.
h) Added the concept of session-less service invocation.
i) Added a generic structure that allows passing any number of attributes to the AddNodes Service.
j) Added requirement to protect against user identity token attacks.
k) Added new EncryptedSecret format for user identity tokens.