Precision Timing for Reliable Power.  Simplified.
Sepam Time Sync


1per10 Protocol Description

1per10 is a simple time sync pulse, one pulse every 10 seconds, to provide a precise external time sync reference.   The rising edge of the first 1per10 pulse occurs at the exact start of a minute, and subsequent pulses follow at 10 second intervals.   Since only the rising edge is used for synchronization, the width (duration) of the pulse is not important.

Note: 1per10 provides a precise sync pulse only (not the full date/time as may be the case with other time protocols), and so the device must first be set to the approximate date/time through other means.

For more details on 1per10 protocol and time-sync options for Sepam relays, see Tech Note: Overview of 1per10 Protocol (TN-104)


Time Sync: Sepam 20/40/80 Protective Relays

Modern industrial/commercial power systems require precise time synchronization of all devices to ensure meaningful data for analysis and reliable operation.   Sepam protective relays, series 20, 40 and 80, from Schneider Electric use 1per10 for precision time sync.   STR-100 Satellite Time Reference and CyTime™ SER-3200/2408 Sequence of Events Recorders from Cyber Sciences can generate the 1per10 signal to synchronize these relays, greatly simplifying time sync design. SER-3200/2408 Event Recorders accept a variety of time source options and then sync with each other using PTP.  In turn, a PTP slave can also output a legacy protocol (e.g., 1per10) to devices that do not support PTP.

Sepam Time Sync Wiring

Sepam relays from Schneider Electric have an internal clock that can be set via software and synchronized via an external 1per10 pulse to achieve precise timestamping of events.   Sepam module MES114 is used and logic input I21 (I103 for Series 80) is designated for this purpose using Sepam setup software.   The synchronization pulse period (one pulse per 10 seconds) is determined automatically by Sepam when it is energized, based on the first two pulses received.

Cyber Sciences offers two products capable of generating the 1per10 signal (at 24 Vdc) compatible with Sepam relays: STR-100 Satellite Time Reference and CyTime™ SER-3200/2408 Sequence of Events Recorders (via a PLX-24V wiring accessory).  To use the STR-100, its channel 2 (CH2) must be configured to output 1per10.   To take advantage of PTP (IEEE 1588) precision time sync over Ethernet, an SER-3200-PTP (or SER-2408-PTP) must be configured as a time sync master with 1per10 as its output (via PLX-24V).

Sepam Setup

Sepam relays can be configured for time sync via an external signal (1per10).  Settings are as follows:

  • Logic input I21 set for external sync (series 20 or series 40)
  • Logic input I103 set for external sync (series 80)
  • Sepam clock must be set within 4 seconds of correct time
  • 1per10 pulse must be operational before Sepam is powered on.

For more details, see Tech Note: Overview of 1per10 Protocol (TN-104)