Appendix a – register addressing conventions, Data-addressing conventions – Black Box GEH-6510 User Manual

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•••• Appendix A – Register Addressing Conventions

DDE Server User’s Guide

Appendix A – Register
Addressing Conventions

Data-Addressing Conventions

The PMCS DDE Server is capable of interpreting both decimal and hexadecimal
addresses. This allows access to the Modbus RTU protocol’s extended register mode.
The two addressing schemes are identical with one exception; in hexadecimal mode,
an “X” is inserted prior to the address number to indicate that the address following
is in hexadecimal format. The R character is ALWAYS present. Items in < >
represent a variable numeric value. Capital letters in brackets [ ] indicate a hard
character that does not change; it is either present or not. Lower-case letters in
brackets [ ] indicate switches that may or may not be present; refer to the following
sections for details.

The basic addressing scheme is as follows:

R indicates a Register
address follows.

f indicates the
register type.

X indicates a address is
hexadecimal. If the X is not
present, the address is read
as decimal.

nnnn is the actual address.
Four characters are required,
so leading zeroes must be
used if necessary. For
example, the correct syntax is
0025 rather than 25.

R <f> <[X] nnnn>

Switches may be used to modify addresses. The possible switches are shown below,
and are detailed in the following sections:

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