Overview

In order to allow a consistent SOE (sequence of events), a unique time reference is needed to synchronize the internal time on each time stamping entity of the system:

  • BME P58 ••••

  • BMX ERT 1604 T

  • BM• CRA 312 10

Time Reference Selection

The following table shows the recommended time reference based on the system architecture:

Time Stamping Module in the System

Recommended Time Reference

Description

The system contains only BME P58 •••• time stamping modules.

NTP server

An NTP server is connected on the control Ethernet network (if such a network is available on the PLC) or on the Ethernet remote I/O network. In the case of a flat architecture, the CPU can be set as an NTP server.

With a unique NTP server available:

  • OFS and SCADA synchronize their time on the NTP server.

  • The BME P58 •••• CPU synchronizes its clock on the same NTP server.

The system contains only BM• CRA 312 10 time stamping modules.

NTP server

An NTP server is connected on the control Ethernet network (if such a network is available on the PLC) or on the Ethernet remote I/O network.

With a unique NTP server available:

  • OFS and SCADA synchronize their time on the NTP server.

  • The BM• CRA 312 10 modules synchronize their clock on the same NTP server.

The system only contains BMX ERT 1604 T modules.

NTP server

An NTP server is connected on the control Ethernet network.

With a unique NTP server available:

  • OFS and SCADA synchronize their time on the NTP server.

IRIG-B 004/5/6/7 or DCF77 time code

The BMX ERT 1604 T modules synchronize their clock on an IRIG-B 004/5/6/7 or DCF77 time code.

The system contains BME P58 ••••, BMX ERT 1604 T, and BM• CRA 312 10 modules.

IRIG-B 004/5/6/7 or DCF77 time code from a GPS signal

The GPS provides the time reference to the time sources.

In this case:

  • OFS and SCADA synchronize their time on an NTP server (dedicated high accuracy hardware synchronized on a GPS receiver).

  • The BME P58 •••• CPU synchronizes its clock on the NTP server.

  • The BM• CRA 312 10 modules synchronize their clock on the same NTP server.

  • The BMX ERT 1604 T modules synchronize their clock on a GPS receiver.

IRIG-B 004/5/6/7 or DCF77 time code from an NTP server (dedicated high accuracy hardware like a Gorgy Timing LEDI Network NTP Server or equivalent)

The hardware NTP server (high accuracy) provides the time reference to the time sources.

In this case:

  • OFS and SCADA synchronize their time on the NTP server.

  • The BME P58 •••• CPU synchronizes its clock on the same NTP server.

  • The BM• CRA 312 10 modules synchronize their clock on the same NTP server.

  • The BMX ERT 1604 T modules synchronize their clock on the IRIG-B 004/5/6/7 or DCF77 output of the same NTP server.

NOTE: As all the time sources are synchronized on the dedicated high accuracy hardware NTP server, a GPS receiver is not mandatory for synchronization.

Time Sources for Modules

The following table defines the time sources recommended for each time stamping event source module:

Module

Time Source

BME P58 ••••

External NTP server (CPU NTP tab configured as an NTP client).

An NTP server has to be available on the Ethernet network accessible from the BME P58 •••• CPU and set in Control Expert.

NOTE: For more details on NTP server configuration in a Modicon M580 CPU, refer to chapter NTP Tab in Modicon M580, Hardware, Reference Manual.

Internal NTP server (CPU NTP tab configured as an NTP server).

The CPU internal clock is used as reference clock. This setting can only be used in the case of a flat architecture.

NOTE: For more details on NTP server configuration in a Modicon M580 CPU, refer to chapter NTP Tab in Modicon M580, Hardware, Reference Manual.

BMX ERT 1604 T

GPS time source (IRIG-B 004/5/6/7 or DCF77 time code).

This solution provides the most accurate time source.

Radio receiver time source (DCF77 time code) based on a radio transmitter based in Germany near Frankfurt with an action range mainly limited to Europe.

NOTE: For more details on clock source connection on the BMX ERT 1604 T module, refer to chapter Physical Implementation in Modicon X80, BMXERT0604T Time Stamp Module, User Guide.

NTP server (IRIG-B 004/5/6/7 or DCF77 time code).

Dedicated high accuracy hardware like a Gorgy Timing LEDI Network NTP Server or equivalent that provides IRIG-B 004/5/6/7 or DCF77 time code outputs.

BM• CRA 312 10

NTP server.

An NTP server has to be available on the Ethernet network accessible from the BM• CRA 312 10 module and set in Control Expert.

NOTE: With a Modicon M580 CPU, NTP server is configured in the CPU embedded Ethernet ports parameters. Refer to topic NTP Tab in Modicon M580, Hardware, Reference Manual.
NOTE: With a Modicon Quantum CPU, NTP server is configured in the CRP communication head module on the local rack. Refer to chapter NTP Configuration in Control Expert in Quantum EIO, Remote I/O Modules, Installation and Configuration Guide.

OFS and SCADA

NTP server.