New Functions in Version V4.02
Connecting an S7-200 to the Multipoint Interface
If you wish to connect an
19.2Kbps in the properties dialog box for the MPI subnet. The following restrictions apply:
SA maximum of 8 nodes are permitted
(CPUs, programming devices/operator panels, communications processors/ function modules with separate MPI addresses (each node must be able to support 19.2 Kbps)).
SGlobal data communication between these nodes is impossible.
SOnly certain
5 | Using Upper and Lower Case for Shared and Local Symbols |
No Distinction Between Upper and Lower Case Characters
In previous versions of STEP 7, the user could define symbols which differed from one another only in the case used for individual characters. This has been changed in STEP 7, V4.02. From this version onwards, it will no longer be possible to distinguish between symbols created in upper and lower case.
This change was made in response to the wishes of our customers, and will greatly reduce the risk of errors occurring in a program. The restrictions which have been made to the symbol definition also support the aims of the PLCopen forum to define a standard for transferable programs.
A symbol definition based solely on the distinction between upper and lower case characters is now no longer supported. For example, in previous versions the following definition was possible in the symbol table:
Motor1 = I 0.0
motor1 = I 1.0
The symbols were distinguished on the basis of the case of the first letter. This type of differentiation carries with it a significant risk of confusion. The new definition eliminates this possible source of errors.
Supplement to the STEP 7 User Manual V4.0 | 11 |