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ProSoft Technology PTQ-PDPMV1 User Manual

Page 154

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Mailbox Messaging

PTQ-PDPMV1 ♦ Quantum Platform

User Manual

PROFIBUS DP Master Network Interface Module for Quantum

Page 154 of 306

ProSoft Technology, Inc.

August 12, 2014

The processor logic required to implement these messaging mailbox exchanges
will be made simpler after the function blocks are provided.

Sending a mailbox message to the PTQ-PDPMV1 module is a relatively simple
process, however, it is important to follow a certain sequence.

Remembering the PROFIBUS Output Data Memory Map:

Quantum
Address
(Example)

Unity Address
(Example)

Relative
Word
Offset

Description

40101

%MW101

0

Last in Mailbox Message ID

40102

%MW102

1

Last Alarm Control index

40103
40104

%MW103
%MW104

2

PROFIBUS CRC32: Computed for PROFIBUS
Config

40105
40106

%MW105
%MW106

4

Module CRC32: computed for module data
When the module first starts up or recognizes an
initialization of the processor, it will compare the
values of the two CRCs in the input and output
images. If either one of the CRCs do not match, the
module will be placed in STOP mode. If each set
matches, the module will be placed in OPERATE
mode.

40107 to
40150

%MW107 to
%MW150

6 to 149

Outgoing Mailbox Data: Mailbox Message command
being sent to the PTQ module

40151 to N

%MW151 to N

150 to N

PROFIBUS Output Data: Data going to the
PROFIBUS network
N is a function of the user-selected size of the
PROFIBUS Output data block. Maximum size is 1536
bytes

The important section relevant to the Mailbox Messaging discussion is the
Outgoing Mailbox Data section (Word Offsets 2 to 145). Within this section of
data, the following structure exists: