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.
The basic addressing scheme is as follows:
R indicates a Register | X indicates a address is |
hexadecimal. If the X is not | |
address follows. | present, the address is read |
| as decimal. |
f indicates the register type.
R <f> <[X] nnnn>
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.
Switches may be used to modify addresses. The possible switches are shown below, and are detailed in the following sections:
80 • Appendix A – Register Addressing Conventions | DDE Server User’s Guide |