1. Introduction
PLCs, with their advantages of simple structure, versatility, convenient programming, high flexibility, and high reliability, have become standard equipment in industrial control and are widely used in industrial automation. However, the development, design, verification, and debugging of PLC control systems still rely on physical models for simulation experiments, a method that is inefficient, costly, and unsafe. Furthermore, PLC control systems require numerous input and output points, which is beyond the capabilities of typical physical models or simulation software. To achieve the desired simulation effect, simulation programs provided by PLC manufacturers are necessary. These programs allow for the design of various input and output devices to simulate both static and dynamic states, and also provide registers, programmable subroutines, timers, counters, and other features for user convenience. Because the simulation programs provided by manufacturers are all for programming interfaces and do not open the connection interface of the configuration software, it is currently a difficult technology for users or developers to combine the human-machine interface with simulation and debugging of the current working condition. Therefore, based on this issue, 3D Force Control has developed various PLC simulation drivers such as PLCsim for Siemens S7300/400 and Emluation5000 for the Ablogix series. With the help of Force Control configuration software, developers can easily and quickly build a simulation model for the PLC control system to verify and debug the developed program.
2. Introduction to Plcsim Functions
Plcsim is a Siemens STEP 7 programming suite used to simulate S7 300/400 hardware devices.
It has the following characteristics,
1) Perform hardware-independent S7 program testing on PC and PG.
2) Eliminate logical errors in the early stages of program development.
3) Reduce development costs, accelerate the development process, and improve program quality.
4) Plcsim can mainly simulate mining operations. Even a simple working condition may consist of various triggering events over a period of time. If you repeatedly debug a certain working condition, it is difficult to rely entirely on manual operation to simulate the event. Plcsim can solve this problem. Programmers can record the manual simulation as an event. For different working conditions, different event files can be recorded. By selecting different event files, different working conditions can be simulated without having to manually input them one by one.
3. Introduction to Emluation5000 Features
RSLogixEmulate5000 is a PCL simulation software provided by Rockwell Automation (USA) for simulating PLC hardware devices, facilitating program testing for developers. It's a Windows-based software package that can simulate one or more Logix 5000 processor workstations. You simply specify which Logix 5000 ladder diagram program to run, and RSLogixEmulate will scan the ladder diagram just like a real processor. For further debugging, RSLogixEmulate can be set to single-scan mode, and an interrupt point can be added to interrupt the scan, but this still differs from a real PLC device. This software is used by AB (Artificial Intelligence) for human-machine interface development. Simply put, it's used for developing displays and designing display screens.
4. Force control software simulation function and structure
a) Addressing the limitation that Siemens PLCSIM simulation software can only be programmed for monitoring and connect to WinCC, ForceControl pioneered the development of a driver library based on PLCSIM's underlying SDK-API functions. This library can effectively connect to PLCSIM and perform the following functions:
i . It can perform stop/run/run-p state transitions on plcsim.
ii . It can communicate and monitor i/q/m/db/c/t/fc/fb.
iii . It can obtain various CPU information from PLCSIM.
iv . It can monitor and simulate 4 accumulators.
v . Can communicate with SFC/SFB/OB blocks. (But does not support FM and CP cards.)
vi . can share plcsim with wincc/step7.
b) For the emulate5000 simulation software of ab, ForceControl developed a driver library based on the emulate5000 underlying layer and combined with rslinx, which can connect well to emulate5000 and perform the following functions.
i . The switching states of the simulated PLC can be accessed and controlled via Plinx.
ii . Access to the hardware I/O card can be emulated by adding softmodul to emulate5000.
iii . Can access any global and local variables in the simulator.
iv . Message variables can be monitored using the msg function block.
v . Can share access to emulate5000 with Rockwell's software.
5. Expanded Applications in the Simulation Industry
a) Rapid engineering configuration: Previously, PLC simulation software only offered a programming interface and couldn't be integrated with HMI software. Major manufacturers also separated their monitoring and simulation software connections, such as PLCsim + WinCC or Emulate5000 + RSView32. However, due to product monopolies and closed interfaces, in the initial stages of engineering configuration, users could only choose expensive software from the same company for visual process simulation, or simply skip visual simulation due to budget constraints. This resulted in high project costs or numerous engineering problems due to the lack of process simulation. Now, the cost-effective domestic ForceControl configuration and monitoring software can be used for rapid engineering configuration and simulation debugging. This also facilitates rapid configuration and process simulation debugging for existing ForceControl software users.
b) Simulation Products: Currently, many simulation process platforms and simulation teaching platforms have emerged in the market. These are primarily designed to save time by using software to simulate the execution of processes in actual equipment. However, most simulation software currently uses code-level programming languages such as VC/VB. This results in long development cycles for interfaces and interfaces, cumbersome code debugging, and prevents developers from focusing on the implementation of process simulations. Furthermore, interface maintenance is difficult in the later stages. However, by combining ForceControl software with PLCSIM/EMulate5000, process and control personnel can directly participate in writing simulation software without the need for code-level programmers. This allows them to configure control loops using high-quality European and American control products while also using the cost-effective ForceControl configuration software to configure complex interface functions, thus breaking free from the price monopoly of using only one company's complete product line. This provides end-users and industry companies with high-value software solutions.
