Micromod RetroPAK: SLC Installation Manual - Manual (Page 38)

MOD 30ML Multiloop Controller
MECHANICAL INSTALLATION
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2.3 USING THE MEMORY MODULE
The optional memory module plugs directly into the CPU board and can be used to back up a
controller database, or transfer a database from one instrument to another.
Figure 2-1. Controller with Memory Module Installed
A controller database can be copied into the Memory Module and the module removed for
safekeeping. Data retention, when the module is not installed on a working instrument, is
typically 10 years. A module installed on a working controller will retain its data much longer.
This provides a known good configuration as a backup. (Note: any changes to tuning
parameters, setpoints etc. that were made by the operator from the controller keypad will be
overwritten).
When a memory module is installed in a working instrument with the write protection off, the
operating software keeps the module up-to-date with all real time changes in the instrument,
including: tuning parameter changes; output values and states; changes made by operators;
calculation results; sequence steps; alarm trip points and values; etc. These changes are
written to the module every 50 milliseconds. Checksums protect the data in the module from
being overwritten by bad data in the event of an instrument failure.
Should a controller need to be replaced, the Memory Module containing the database for that
controller can be plugged into a new controller and the database will be instantly transferred
to the new controller when it is plugged into the housing (with power applied). This allows
rapid replacement of controllers without programming. If the memory module was being
updated by the old controller, the last good values of all parameters will also be loaded into
the new controllers.
The controller provides the option to automatically download from an installed Memory
Module after a loss of power. This option must be selected during initial configuration of the
controller.
2.3.1 Memory Module Installation Procedure
If the Portable Memory Module is to be used, install as follows:
1. Loosen the 2 retaining screws in the front panel, Figure 1-1, and pull the instrument out
of its housing.
! CAUTION:
Support the instrument from the front and bottom or from the insulator
plate whenever the instrument is outside its housing. Do not allow the full
weight of the circuit boards to be suspended unsupported from the front
panel as this may overstress the brackets at that end.