Rockwell Automation 57C423 Common Memory Module - Manual (Page 7)

1Ć1
1.0 INTRODUCTION
The products described in this instruction manual are manufactured
or distributed by Reliance Electric Industrial Company.
The Common Memory module (57C413B and 57C423)is required in
slot 0 of a DCS 5000/AutoMax rack that contains more than one
Processor module. The Common Memory module stores the
configuration data that must be shared among Processors, such as
definitions of physical I/O. This frees Processor module memory for
application tasks. The Common Memory module also arbitrates the
Processors' access to the bus.
The Common Memory module may also be placed in slot 0 of
a singleĆProcessor rack. As in the case above, the configuration data
which normally resides on the Processor module in a
singleĆProcessor rack is stored on the Common Memory module.
When the Common Memory module is placed in any even slot other
than 0, it is used for userĆdefinable data storage only. This mode is
useful if you need to control explicitly the physical allocation of
memory, e.g., to define consecutive registers for shaft register
instructions. Note, however, that it is not possible to define arrays in
this mode.
The module incorporates bus arbitration logic, a system watchdog
for multiĆprocessing, and batteryĆbacked RAM for data storage.
When used in slot 0, M/N 57C413B has 128K bytes (64K registers)of
memory; M/N 57C423 has 256K bytes (128K registers)of memory.
Both versions of the module make available 128K bytes only when
used in any even slot other than 0. An onĆboard lithium battery and a
superĆcapacitor protect the Common Memory module from power
failures. Note that the battery backup is designed to maintain the
contents of RAM only. It is not a source of uninterruptible power.
Should the rack lose power, the onĆboard battery can maintain the
contents of RAM for a minimum of 600 days.
This manual describes the functions and specifications of the
module. It also includes a detailed overview of installation and
servicing procedures, as well as examples of programming methods.
Unless specifically noted otherwise, the information in this manual
describes both the M/N 57C413B and M/N 57C423 Common
Memory modules.
Related publications that may be of interest:
D JĆ3630 ReSource AutoMax PROGRAMMING
EXECUTIVE INSTRUCTION MANUAL
VERSION 1.0
D JĆ3649 AutoMax CONFIGURATION TASK MANUAL
D JĆ3650 AutoMax PROCESSOR MODULE INSTRUCTION
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D JĆ3675 AutoMax ENHANCED BASIC LANGUAGE
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D JĆ3676 AutoMax CONTROL BLOCK LANGUAGE
INSTRUCTION MANUAL
D JĆ3677 AutoMax LADDER LOGIC LANGUAGE
INSTRUCTION MANUAL