Siemens SIMATIC PCS 7 Configuration Manual page 154

Configuring AS functions
8.1 Principles
library blocks is the fact that they are serviced and maintained systematically, including with
regard to different PCS 7 versions. Project teams can save time and cost as a result, particularly
for future upgrades where the original project team may no longer be available.
Criteria to consider when making decisions about creating user-defined blocks
The following points must be reviewed before creating user-defined blocks:
● What functions do any existing PCS 7 block libraries offer (e.g. PCS 7 add-on catalog) in
terms of meeting your requirements?
● Does a sector-specific library already exist which meets your requirements?
● Can an existing PCS 7 block library be adapted to meet your requirements, e.g. related to
the display?
● Is just one block to be created, or several blocks?
● Is there a description or specification of the functions required of the blocks to be created?
● Can user-defined blocks be maintained and serviced in the future?
Guidelines on the range of numbers
The block range of numbers for AS blocks is already allocated for the range from 0 to 2499 by
the standard, add-on and sector-specific libraries. The FB range of numbers is therefore
divided up as follows:
● Up to FB1000: Allocated with existing PCS 7 block libraries
● FB 1800-1999: Reserved for the PCS 7 system
● FB 1025 and above: Provided for SFC types
● FB 2000- 2014: Allocation for the SIMOCODE Pro library
The numbers in the range from 2500 to 2599 should be used for creating user-defined blocks.
Note
Please note that the following CPU types do not support a block range of numbers greater
than 2048:
● CPUs 412-416 with V4.x version
● H-CPU 412 and 414 with V4.x version
Numbers in the range from 1200 to 1249 are recommended when using user-defined blocks
on these CPU types.
Guidelines on naming
The system has a limit of 16 characters for symbolic names for function blocks. However, a
maximum of 8 characters is recommended on account of the display in the CFC Editor.
Symbolic names with more than 8 characters are not displayed in full in the CFC Editor for
summary reasons.
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Compendium Part A - Configuration Guidelines (V8.2)
Configuration Manual, 08/2016, A5E38166869-AA