The fieldbus data link layer provide basic time-critical messaging communication between devices in an automation environment. The purpose of this part of IEC 61158 is to define eight distinct and non- interoperable fieldbus Data link protocols. Each protocol defined in this standard is most most closely related to and lies within the field of application of the corresponding services of IEC 61158-3. the fieldbus data link services definition .

• Year of Declaration: 2003
• Reference: IEC 61158-4
• Number of Pages: 1096
• Code: GYS IEC 61158-4
• Version: Third edition 2003
• ICS Number: 25.040 -35.100.35.240.50