Overview of Momentum M1 Processor Adapters
24 870 USE 101 10 V.2
Memory and Performance Characteristics
Introduction Processor Adapters are equipped with internal memory and Flash RAM. This
section explains those two types of memory and describes the memory size and
performance characteristics of each Processor Adapter.
Internal Memory Internal memory includes user memory and state RAM:
lUser memory contains the control logic program and such system overhead as
the Processor Adapter configuration, I/O mapping, checksum and system
diagnostics.
lState RAM is the area in memory where all the input and output references for
program and control operations are defined and returned.
The user may change the way internal memory is allocated by adjusting
parameters for user memory and state RAM.
Flash RAM Flash RAM contains the executive firmware, which is the operating system for the
PLC. It also contains a firmware kernel, which cannot be changed. The kernel is a
small portion of memory that recognizes acceptab le executive firmware packages
and allows them to be downloaded to the Processor Adapter.
Space is also provided in Flash so that a copy of the user program and state RAM
values can be stored. This back-up capability is particularly useful in configu rations
where no battery is used (i.e., a Processor Adapter without an Option Adapter).
When the module is successfully communicating with other devices, if a ring
adapter with battery back up is not present, it is recommended that you stop the
processor and save the user program to Flash. This will save the processor’s ARP
cache and enable it to “remember” this information if power is lost or removed.
This procedure should also be followed whenever:
lA new or substitute device is installed on the network;
lThe IP address of a network device has been changed.
Continued on next page
Note: Some processors run both IEC and Ladder Logic and some run only IEC.
See table following.