Chapter 4
Basic Programming Techniques
4-6
General Rules for Using MMS Named Variables
The MMS protocol allows you to associate a name with an address within
the node. These associated names are called MMS named variables. It is
easier, for example, to remember Paint_station_1 than it is to remember
N12:1 (figure 4.3). You can define MMS named variables and use them
within command lines when programming.
Figure 4.3
MMS Named Variables are Easier to Remember
Part_count_1
N12:1
MMS Named Variables are
easier to remember
than addresses within a node.
I - 12422
You define MMS named variables by using the DEFVAR command (this
command is covered in detail in the section titled Defining MMS Named
Variables, later in this chapter).
There are rules for the using MMS named variables. Both local and
remote variables:
must be in single quotes
can be up to 32 characters long
can contain letters A to Z (both upper and lower case)
can contain an underscore (_) and a dollar sign ($)
can contain numerals 0 through 9
cannot
start with a numeral
must be in proper symbol format for local/remote device
For example:
’I_am_an_MMS_Named_Variable’
General Rules for Using Address Strings (MMS Unnamed Variables)
There are rules for the use of address strings (MMS unnamed variables)
within PLC–5 message block syntax. Both local and remote address
strings:
must be in double quotes
can be up to 32 characters long
must be in proper address format for local/remote device
Summary of Contents for PLC-5 MAP/OSI
Page 1: ...PLC 5 MAP OSI Software User Manual Cat No 1785 OSI AB Parts...
Page 4: ...Table of Contents iii OSI Layer Management E 1...
Page 57: ...Chapter 4 Basic Programming Techniques 4 7 For example B7 6 10 AB Parts...
Page 91: ...Mapping MMS Data Types onto PLC 5 40 5 60 File Types Appendix A A 2 T ACC D 16 AB Parts...