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Selecting a Program Block
There are three Program Blocks on a diskette. Select the Program Block that provides the level of functionality and performance required for the application.
Program Block | Number of I/O | Maximum Number | Compatible CPUs |
Identifier | Link Modules | of References |
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LINK73X | 1 | 512points | 731/732,771/772,781/782 |
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LINK77X | 2 | 2048points | 771/772,781/782 |
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LINK78X | 4 | 4096points | 781/782 |
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The LINK73X Program Block provides the fastest update speed and has the lowest memory requirements, but is limited to a single I/O Link Interface Module per 90±70 system and 512 I/O points. LINK77X provides up to two I/O Link Interface Modules per 90±70 PLC and 2048 I/O points, but it is slightly slower and requires more memory. LINK78X accommodates up to four I/O Link Interface Modules per PLC and provides up to 4096 I/O points. Its update rate is slower than the other two Program Blocks, and it uses more memory.
For the 731/732 CPU, the LINK73X Program Block is required. For the 771/772 CPU, either LINK73X or LINK77X can be used. For the 781/782 CPU, any of the three Program Blocks can be used. Remember that the smaller Program Blocks will give better performance.
Adding the Program Block Logic to an Application Program
To add a Program Block to an application program, follow these steps:
1.Copy the selected Program Block library file from the diskette to the Logicmaster 90±70 library directory(suchas:c:\lm90\p70\p70_lib).
2.Using the Librarian function (available with Logicmaster 90±70 version 3.0 or later), import the Program Block into the working folder.
3.If the application program will use nicknames for the Program Block %P references (see page 27), include the nicknames in the Variable Declaration Table. The nicknames are provided as three .SDE files in the program folder on the application software diskette: LINK73SX.SDE, LINK77SX.SDE, and LINK78SX.SDE. To include the appropriate file, go to the Variable Declarations in the working folder, select ªincludeº, and enter the path and filename (such as: c:\link\link73sx.sde).
4.Complete the application program logic as described on the following pages.
24 | Series |
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