SFB USEND Response times are valid for the following modules:
• for MPI: 2 x CPU 388 and 2 x CPU 488 SFB USEND 26 39 59 140 28 42 58 143 0 20 40 60 80 100 120 140 160 8 64 160 400
useful data in bytes
∅
∅ response time in ms
388 488
SFB BSEND Response times are valid for the following modules:
• for MPI: 2 x CPU 388 and 2 x CPU 488 SFB BSEND 44 57 80 158 47 59 83 161 0 20 40 60 80 100 120 140 160 180 8 64 160 400
useful data in bytes
∅
∅ response time in ms
388 488
Response times for larger amounts of useful data:
Appendix
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A-27 SFB PUT/GET Response times are valid for the following modules:
• for MPI: 2 x CPU 388 and 2 x CPU 488 SFB PUT/GET 39 51 76 144 42 54 79 147 0 20 40 60 80 100 120 140 160 8 64 160 400
useful data in bytes
∅
∅ response time in ms
388 488
SFC X_SEND The following graph compares two different response times. With short response times, the connections are maintained; with longer response times, the connections are set up and cleared again for each data trans- mission.
Response times are valid for the following modules:
• für MPI: 2 x CPU 388 und 2 x CPU 488 SFC X_SEND 44 49 57 59 143 149 157 159 47 51 59 62 145 150 157 160 0 20 40 60 80 100 120 140 160
8 32 64 76 useful data in bytes
∅
∅ response time in ms
Connections remain 388 C. are set up/cleared 388 Connections remain 488 C. are set up/cleared 488
Appendix
SFC X_PUT/X_GET The following graph compares two different response times. With short response times, the connections are maintained; with longer response times, the connections are set up and cleared again for each data trans- mission.
Response times are valid for the following modules:
• for MPI: 2 x CPU 388 and CPU 388 with CPU 215-2 SFC X_PUT/X_GET 38 45 52 54 140 145 152 155 100 100 100 100 300 300 300 300 0 50 100 150 200 250 300
8 32 64 76 useful data in bytes
∅
∅ response time in ms
Connections remain C. are set up/cleared C. with 215 remain C. with 215 set up/cleared
SFC X_PUT/X_GET The following graph compares two different response times. With short response times, the connections are maintained; with longer response times, the connections are set up and cleared again for each data trans- mission.
Response times are valid for the following modules:
• for MPI: 2 x CPU 488 and CPU 488 with CPU 215-2 SFC X_PUT/X_GET 45 48 54 57 145 150 157 160 100 100 100 100 400 400 400 400 50 100 150 200 250 300 350 400 ∅ ∅ response time in ms Connections remain C. are set up/cleared C. with 215 remain C. with 215 set up/cleared
Appendix
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A-29
Glossary
Address An address is the designation for a specific operand or operand area, e.g. input I12.1; flag word FW25; data block DB3.
Address Assignment
Assigning an address in the user program. Addresses can be assigned to specific operands or operand areas (e.g. input I12.1; flag word FW25).
AT Advanced Technology. AT designates the PC standard of the second gen-
eration, i.e. PCs with the ISA bus (16-bit data lines and 24-bit address lines), Intel processors >= 80286, two interrupt controllers and hard disk.
BIOS Basic Input Output System - The term BIOS refers to the part of the soft-
ware that establishes the link between the hardware and the operating system drivers. The BIOS translates the hardware base into an abstract; the associated software is stored in an EPROM. The most important com- ponents are, for example, the loader for the boot sector, the (hardware) SETUP for specifying the hardware configuration and for setting the time of day.
Client/Server Principle
When data is exchanged in accordance with the client/server principle, the client always issues the communications tasks and the server executes them.
COM Configuration Management - Configuration software for SIMATIC NET
communication processors.
Complete Restart When a CPU starts up (following mode switching from STOP to RUN or by switching ON at the main switch), and before cyclic program processing starts (OB1), either the organization block OB101 (warm restart, only for S7-400) or the organization block OB 100 (complete restart) is first proc- essed. In the case of a complete restart, the process image of the inputs is read in and the STEP 7 user program is executed starting with the first command in OB1.
Configuration This is the installation-specific combination of hardware and/or software components.
Configuring This is the process of selecting and combining the separate components of an automation system or installing the required software (e.g. operating system on the M7 automation computer) and adapting it to the specific application (e.g. by parameterizing the modules).
Control Command FREEZE
The DP master sends the control command FREEZE to a group of DP slaves and causes the DP slaves to freeze the status of their inputs at the current value.
Appendix
Control Command SYNC
The DP master sends the control command SYNC to a group of DP slaves and causes the DP slaves to synchronize the status of their outputs.
CP Communication Processor - Communication module for installing in a
computer or programmable controller. CPU (Central
Processing Unit)
The CPU is the central processing unit of the programmable controller or computer comprising control and computing mechanisms, memory, op- erating system and interfaces to signal modules and function modules. Cycle Time The cycle time is the time that the CPU requires for processing the user
program once.
Data Block (DB) In technical terms, a data block is a block of data whose operand is loaded into the address register of the DB on opening. It provides memory space and data for all (global) code blocks (FC, FB or OB) that are to be exe- cuted. In contrast, the task of an instance data block is to act as special memory and data for the function block to which it has been assigned. Data Consistency Data area that can be read or written by the operating system as a block in
the case of S7-300/400 CPUs (e.g. PUT/GET). This data area is inde- pendent of the size of useful data actually transferred by the communica- tions functions.
An array of the data types byte, word or double word can be transferred consistent up to a maximum length that depends on the CPU used.
DB Data blocks are data areas in the user program that contain user data.
There are global data blocks that can be accessed by all code blocks and instance data blocks that are assigned to a specific FB call.
DDE Dynamic Data Exchange - This is a communications mechanism that al-
lows Windows applications running in parallel to communicate with each other. DDE makes a distinction between the server and the client. The client sends a task to the server via DDE which the server then executes. DLL Dynamic Link Library - This is a collection of functions that are available
to several programs but which are only loaded into the memory once (Windows/Windows NT feature)
DP Distributed I/O comprises input and output modules that are implemented
decentralized with respect to the CPU (central processing unit of the controller). The SIMATIC system is linked to the distributed I/O via the PROFIBUS-DP bus system.
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A-31
DPRAM Dual Port Random Access Memory - This allows simultaneous access
from two computing components (CP and CPU) on one memory module (RAM).
ESD Guidelines Guidelines for the protection of Electrostatically Sensitive Devices.
FB Function Blocks, according to the IEC 1131-3 standard, are "code blocks with memory". A function block allows parameters to be transferred to the user program. This means that FBs are especially suitable for program- ming frequently recurring complex functions such as closed-loop control and mode selection. Since an FB has a memory (instance data block) its parameters (e.g. outputs) can be accessed at any time and at any point in the user program.
FCs Function Calls are in accordance with the IEC 1131-3 standard "code
blocks without memory". A function call allows parameters to be trans- ferred to the user program. This means that function calls are especially suitable for programming frequently recurring complex functions such as calculations. Important: Due to the lack of memory, the calculated values must be processed immediately after the FC call.
FDL Fieldbus Data Link - Layer 2 of the ISO reference model in the case of
PROFIBUS; it comprises the sublayers "Fieldbus Link Control" (FCL) and "Medium Access Control" (MAC).
FM A Function Module (FM) is a module that relieves loading on the CPU in the S7-300 and S7-400 programmable controllers caused by time-critical or memory-intensive process signal processing tasks. FMs usually use the internal communications bus for high-speed data exchange with the CPU. Examples of FM applications include counting, positioning and closed-loop control.
FMS Fieldbus Message Specification - This constitutes the upper sublayer of
Layer 7 of the ISO reference model for PROFIBUS; it comprises the pro- tocol machine functions, generating the -> PDUs as well as encod- ing/decoding and interpretation of the protocol data unit.
FMS Protocol Protocol for data transfer via the PROFIBUS network in accordance with the Fieldbus Message Specification.
HMI Human-machine interface: HMI systems can access the data areas of an
S7 CPU or S7 objects of an M7. Process data can be visualized appropri- ately on HMI systems and operator control of installations is possible.
IM Interface Module (input/output module)
Industrial Ethernet Bus system for industrial use based on Ethernet (previously called SINEC H1).
Appendix
Installation The installation is the sum total of all electrical equipment. An installation includes programmable controllers, human-machine interfaces, bus sys- tems, field devices, drives, supply leads.
Instance This constitutes the call for a function block. Supposing a function block is called five times in the STEP 7 user program, then five instances exist. An instance data block is assigned to each call.
Instance Data Block (DB)
An instance data block stores the formal parameters and static local data for function blocks. An instance data block can be assigned to an FB call or to a call hierarchy of function blocks.
IRQ Interrupt Request
ISA Industrial System Architecture - PC bus standard; ISA bus - Expansion bus
for XT and AT computers (standardized 16-bit data and 24-bit address bus).
ISO International Standard Organization - International organization based in
Geneva which produces general standards, especially in the data trans- mission field.
Link Table Tables for defining the communication links between programmable mod- ules in a network.
Load into PLC Loadable objects (e.g. code blocks) are loaded from the programming device into the load memory of a programmable module. This can take place via a programming device that is directly connected to the CPU or, for example, via PROFIBUS.
Load into Programming Device
Loadable objects (e.g. code blocks) are loaded from the load memory of the CPU into the programming device. This can take place via a pro- gramming device that is directly connected to the CPU or, for example, via PROFIBUS.
Logical Address This is the address under which a user program in the PLC can access an I/O signal.
Logical Base Address
Logical address of the first I/O signal of a module.
M7 RMOS32 M7 RMOS32 is the 32-bit real-time multi-tasking operating system for the M7 automation computer. M7 RMOS32 contains the M7 RMOS32 kernel and the M7 server as well as utility programs (RT, RFS, CLI, Debugger)
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A-33 M7–API M7–API (Application Programming Interface) is the call interface that is
available to an M7 RMOS32 user program for the purpose of using the services of the M7 server.
Memory Reset (MRES)
The following memory areas of the CPU are reset on memory reset:
• User memory
• Read/write area of the load memory
• System memory with the exception of the MPI parameters and the diagnostics buffer.
MPI The Multi Point Interface is the programming device interface for SIMATIC S7. It allows simultaneous use of several programming devices, text displays and operator panels on one or more CPUs. The stations connected to MPI are interconnected via a bus system.
MPI Address In an MPI network, a unique MPI address has to be assigned to each
programmable module.
MS-DOS Microsoft Disk Operating System is an operating system produced by the
Microsoft company. In the case of M7 RMOS32, the MS-DOS operating system as well as an MS-DOS application can execute as an autonomous, low-priority M7 RMOS32 task.
Network A network comprises one or more coupled subnets with any number of
stations. Several networks can exist alongside each other. A common node table exists for each subnet.
Network Transition This is a connection point between subnets that belong to an overall net- work. This can also be a transition between subnets/networks that have different characteristics (e.g. transition between PROFIBUS and Industrial Ethernet).
OCX OLE Custom Controls
OLE Object Linking and Embedding is the central architectural principle of the Windows versions Windows 95 and Windows NT 3.5 as well as forming the basis of the Windows applications software under Windows for Work- groups 3.11.
Appendix
Operating Mode The following operating modes can be set using the operating mode switch on the CPU :
• RUN with access to the STEP 7 user program, e.g. using the pro- gramming device (RUN-P)
• RUN with access protection (RUN)
• STOP and
• Memory reset (MRES).
Operating State The SIMATIC S7 system family features five different operating states: MEMORY RESET, STOP, START-UP, HALT and RUN. In the case of M7, the operating states are processed by the OMT server. The M7 RMOS32 user program can only take into account the operating states of the M7 when it is explicitly informed by the OMT server or FC server (only for START-UP and RUN).
Operating State RUN
In the RUN operating state, the user program is executed and the process image is updated cyclically. All digital outputs are enabled.
Operating State HALT
Changeover to the HALT operating state takes place from the RUN state in response to a request from the programming device. In this operating state, special test functions are possible.
Operating State START-UP
The START-UP operating state is executed during transition from the STOP operating state to the RUN operating state. It can be triggered by the mode switch or following network ON or by entering commands at the programming device. In the case of the S7-300 a complete restart takes place. In the case of the S7-400, either a complete restart or a warm re- start takes place depending on the position of the start-up mode switch. Operating State
STOP
Changeover to the STOP state takes place as a result of:
• Operating the operating mode switch
• An internal fault on the CPU
• A command entered at the programming device
In the "STOP" operating state, the user program does not execute. All modules are switched into a safe state. Certain programming functions and operator control and visualization functions are possible.
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PC Personal Computer
PCMCIA Personal Computer Memory Card International Association - Association of about 450 member companies in the computer sector that aims to specify worldwide standards for the miniaturization and flexible use of PC expansion cards and to make this standard technology available on the market. It cooperates with JEIDA (PC card standard for compact PC ex- pansion modules).
PDU Protocol Data Unit
PG Programming device for the SIMATIC product family of Siemens AG; used
for programming, configuration, maintenance and for service.
PLC Programmable Logic Controller - PLCs are electronic controllers whose
functions are stored in the controller in the form of a program. Their hardware configuration and wiring is therefore independent of the function of the controller.
The PLC has the structure of a computer; it comprises a CPU with memory, input/output modules and an internal bus. The peripherals and the programming language are optimized for the controller technology. Procedure The sequence for data transfer in accordance with a specific technique in
ISO level 2 is also termed a procedure in the case of the point-to-point link.
Process Image The signal states for the digital input and output modules are stored in the CPU in a process image. A distinction is made between the process image for the inputs (PII) and the process image for the outputs (PIO).
Process Image for the Inputs (PII)
The process image for the inputs is read from the input modules by the operating system before the user program is executed.
Process Image for the Outputs (PIO)
The process image for the outputs is transferred to the output modules at the end of the user program by the operating system.
PROFIBUS Process Field Bus - A fieldbus to the EN 50170 standard Vol. 2
PROFIBUS (DIN 19245; bus system for industrial use based on PROFIBUS; previously known as SINEC L2).
PROFIBUS-DP DP operating mode to DIN E 19245, Part 3; PROFIBUS-DP is a serial bus, specially developed by SIEMENS for the field level used to link to distant (distributed) I/O (previously know as L2/DP).
Project An S7 project encompasses all objects of an automation solution regard- less of the number of stations, modules and their networking.
Appendix
Protocol This is a procedural specification for the process of transferring data. It defines both the formats of the messages and the data flow during trans- fer.
Rack A rack is a module rack comprising slots in which modules are inserted.
S7 Manager STEP 7 tool. All configuration and parameterization required for a
SIMATIC S7 system can be performed under the user interface of the S7 Manager.
S7 Object S7 objects on an M7 represent the operand area of an S7 CPU. Via S7
objects, an M7 can communicate with other SIMATIC components (e.g. HMI systems, programming devices, S7 CPUs). S7 objects are created and managed by the "Object server". S7 objects of an M7 comprise, for example, all process data, data blocks or bit memory areas.
S7 PLC This is an abbreviation for a programmable logic controller of the
SIMATIC S7 product family of Siemens AG.
S7 Program The S7 program encompasses blocks, source code and schedules for
programmable S7 modules.
S7 Protocol The S7 protocol (also known as "S7 communication" or "S7 functions") forms a simple and efficient interface between SIMATIC S7 stations and to the programming device or PC.
SCSI Small Computer System Interface - Interface for connecting SCSI devices
(e.g. hard disk drives, CD-ROM drives).
Services These are the services offered by a communication protocol.