ProSoft Technology 5204SE-MNET-PDPMV1 - Manual (Page 60)

5204SE-MNET-PDPMV1 ♦ ProLinx Gateway Procedures
Modbus TCP/IP to PROFIBUS DP-V1 Pass-Through Master User Manual
Page 60 of 235
ProSoft Technology, Inc.
December 22, 2009
3.6.2 Configure the Memory Size for the Processor
The processor memory maps that you viewed in and exported from ProSoft
Configuration Builder (PCB) will be imported into the Unity Pro project. These
processor State RAM maps are calculated from the starting memory addresses
and register counts entered into PCB for the module's input and output data
images. For more information on configuring memory addresses in PCB, refer to
Configure the Gateway (page 32).
Allocating processor memory to store input and output data is part of the
processor configuration process. You should view the memory configuration in
the PCB Processor Memory Maps before you begin to allocate memory
addresses in Unity Pro.
Some points to keep in mind are:
ƒ As the programmer, you must be aware of the memory spaces that are
available when deploying in an existing system and assign values to the
Modicon processor and 5204SE-MNET-PDPMV1 configurations accordingly.
ƒ The Modicon M340 processor has a maximum %MW memory allocation size
limit of 32,464 16-bit registers. The default size is 1024 registers. While
setting the %MW memory allocation, you must allocate enough total memory
to accommodate the amount required for the 5204SE-MNET-PDPMV1
gateway as well as for the rest of your application.
ƒ The total number of data registers allocated for PROFIBUS data must at least
equal or exceed the number needed, which can be calculated by taking the
starting register configured in PCB and adding the register count configured,
plus any additional registers required for the rest of the application process
logic. The memory map from PCB can help you determine these numbers.
ƒ The gateway can use up to 768 words of cyclic input data, 768 words of
cyclic output data, 76 words of status data, and 378 words of standard
PROFIBUS slave diagnostic data. Therefore, the total %MW memory
requirement for just the PROFIBUS application could be as much as 1990
words. Round this up to an even 2000 registers as the amount of %MW
memory to allocate for PROFIBUS data.
ƒ You must allocate at least this much memory space as a continuous,
uninterrupted block of processor memory that will not be used by any I/O
modules, processes, or variables.
WARNING: Failure to properly map your processor memory will likely cause corruption of
PROFIBUS data and can create potentially hazardous situations resulting from unexpected
equipment operation; which can result in injury to personnel or damage to equipment.