Doc: ps2001-5-1101-001 Rev: R02. 00
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1486357009-URS, URS
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- 4.2.3 Third-party modules
- Application module requirements
| Communications (39) Communication modules will be provided for the following types of communication • Simple CPU-CPU communications over Ethernet TCP/IP using GET/PUT 13 functions (maximum transfer 880 bytes for S, 160 bytes for S) • Comprehensive CPU-CPU communications over Ethernet TCP/IP with a transfer capability of 64 kilobytes (not applicable to S) • RS 14 point-to-point communications (40) Communication modules may be asynchronous 15 4.2.3 Third-party modules (1) There will be no third-party modules included with the software module library however, provision will be made in the structure of the library to allow third-party modules to be installed (i.e. space must be allocated for such modules. 13 GET/PUT are Simatic functions that are built into Sand S Controllers to allow data to be fetched (GET) from a remote Controller or sent (PUT) to a remote Controller. RS (Recommended Standard 232 and 485) are serial communication protocols 232 uses voltage signals, 485 uses current (and can have longer cable runs, up to 1.2 km) Asynchronous not synchronised to a Controller cycle (may need more than one cycle. 50-71 Doc PS Rev Rb Application module requirements (1) Application modules give structure to the projects that will be developed with the software module library. While it is appreciated that the application blocks, their presence or absence and their content is entirely dependent on the application being controlled a series of typical application modules will be included with the software byway of example. (2) The application modules will have a predetermined order of execution, an example of such a predetermined order is given below (the numbers show the order of execution, this may be used as the basis for the application modules being developed for this project (it is a basis in that it reflects the types of standard modules, but is only an initial concept and may be expanded upon 1 System functions 2 Read instruments (both digital and analogue) 3 Interlock handling 4 Safety system handling 5 Calculation coordination 6 Continuous logic control 7 Sequential logic control 8 Command execution 9 Device handling (control loops) 10 Device driver handling (valves and drives) 11 Alarm handling 12 Communications |