7 - retention, What is retention, Chapter 7 – Rockwell Automation 1760-xxxx Pico Controller User Manual User Manual

Page 151: Retention, What is retention? -1, Chapter

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Publication 1760-UM001D-EN-P - September 2005

Chapter

7

Retention

What is Retention?

Some system and machine controllers for operating states or actual
values require retentive settings. What this means is that values are
retained even after power to a machine or system has been turned off
and are retained until the actual value is overwritten.

Pico Models with Data Retention

Retentive values can be set with 1760-L12BWB-xx and
1760-L12DWD-xx (via the SYSTEM menu) as well as 1760-L18xxx for
the following markers and function relays.

Retentive Markers and Function Relays

It is possible to retentively store (non-volatile memory) the actual
values (status) of markers, timing relays, and up/down counters. The
following markers and function relays can be set to have retentive
actual values:

The Retention setting applies to all of the relays listed above.
Individual markers or function relays cannot be set retentively.

1760-L12BWB-xx, 1760-L12DWD

Marker Relays

M13, M14, M15, M16

Timing Relay

T8

Up/Down Counter

C8

1760-L18xxx

Markers

M13, M14, M15, M16

Text Function Relays

D1 through D8

Timing Relays

T7, T8

Up/Down Counters

C5, C6, C7, C8

TIP

The retentive data is written to an EEPROM every
time the power is turned off. Data security is thereby
assured for 100,000 power cycles.

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