Abstract: This paper introduces the application of PROFIBUS fieldbus technology in PKS system, and realizes the control of ABB ACS800 inverter and intelligent motor center M102 using PROFIBUS-DP bus. The paper mainly discusses the following three aspects: PKS system planning, PROFIBUS network configuration, and PROFIBUS communication and device control in PKS. Keywords: PKS ; PROFIBUS; INVERTER; M102 With the widespread application of large-scale PLCs and DCSs in factories, the modernization level of enterprises has been greatly improved. However, due to the increasing number of electrical devices, the traditional hard-wiring method has led to a significant increase in cables in the control room. Furthermore, interference issues with electrical equipment are difficult to resolve, posing numerous challenges to the maintenance of DCS (PLC) and electrical equipment. With the continuous development and improvement of fieldbus technology, these problems have been readily solved. PROFIBUS is a widely used fieldbus technology; it is an international open fieldbus standard and an open digital communication system with a wide range of applications. This article mainly discusses the solution for Honeywell's PKS system to communicate and control with ABB frequency converters and intelligent motor center (M102-P) via PROFIBUS fieldbus. 1. Experion PKS System Planning Experion PKS is Honeywell's latest DCS control system. It uses a Windows 2000-based server, utilizes a high-speed dynamic buffer to acquire real-time data, and integrates the latest control technologies, fieldbus, and advanced control applications. In terms of fieldbus, it supports multiple popular bus methods such as FF, PROFIBUS, and Device NET, thus possessing strong openness and facilitating communication with third-party systems, instruments, and equipment. This PKS system mainly consists of three network layers: FTE (Fault-Resistant Ethernet), ControlNet (CNET) network, and PROFIBUS network, as shown in Figure 1. FTE is a Honeywell patented technology that enables commercial 100Mbps Ethernet to be fault-tolerant, allowing for all single-point failures and some multi-point failures; switching speeds can be as fast as 1 second, and it provides more communication paths than ordinary Ethernet. ControlNet is a token bus network, also employing redundancy, with a communication speed maintained at 5 Mbits/s (distance-independent). The software used for programming the control system is Control Builder, whose configuration is entirely graphical. The system's control program is based on CMs (Control Modules), which can be individually installed and downloaded from the controller, allowing online modification without affecting the normal operation of the equipment. Various function blocks (including fieldbus function blocks) can be added to the CM, and these function blocks can communicate and interlock with each other. The Experion PKS to PROFIBUS DP interface provides a communication path between the PROFIBUS network and the controller through a dedicated hardware interface card. PROFIBUS Interface Module (PBIM) is a rack-mounted module that allows direct connection between the controller and PROFIBUS devices. PBIM is the master device in the PROFIBUS network, and other devices are slave devices. PBIM allows the controller to directly access devices in the PROFIBUS DP network. The interface module supports devices including motor drives (including frequency converters) and encoders, as well as programmable logic controllers. In this system, three independent PROFIBUS network segments are used, two of which control ordinary motors through M102, and the other communicates and controls the frequency converter. Figure 1 PKS system network diagram 2 PROFIBUS DP network configuration To realize communication and control between DCS and ABB frequency converters and M102, the first step is to complete the PROFIBUS network configuration in DCS. The configuration is designed from the following four aspects. (1) Network design: mainly considering communication speed, number of slave stations, redundancy and safety. Because the communication rates of the frequency converter and M102 are different, and in order to prevent interference from the frequency converter, we place the frequency converter and M102 in different network segments; and place the backup devices in the process flow in different network segments. (2) Hardware connection: Connect each frequency converter or M102 to the corresponding PROFIBUS interface module (master module) in the PKS system according to the design. The master module stores the network configuration through FLASH-ROM and supports automatic reconfiguration of slave devices after power failure. (3) Install GSD file: Each PROFIBUS communication device has a GSD file provided by the manufacturer. The corresponding GSD file needs to be installed before configuration. The GSD files of the frequency converter and M102 are ABB_0812.GSD and INTC08DD.gsd, respectively. (4) Configuration: Add the master station and slave station in DCS to the network respectively. Set the network address of the master station and slave station, select the correct module for each slave station, and configure the main parameters. 2.1 M102 Configuration Settings According to the process requirements, the backup electrical equipment is connected to two different PROFIBUS networks (two independent networks formed by two PBIMs), which is completed using the SST PROFIBUS configuration tool. After adding the M102's GSD file, M102_Motor_Control can be seen in the corresponding slave library. Figure 2 shows the network configuration diagram of the intelligent motor center M102. SST_PFB_CLX_MASTER in the figure is the PROFIBUS communication card of the PKS system, which acts as the network master station with station number 000. M102 acts as a slave station, with station numbers starting from 001. M102 supports multiple data structures. Through comparison, we chose the 8-byte input/2-byte output method, which ensures that more data can be read without affecting network speed. On one end of M102, the corresponding station number (which must be the same as in PKS) is set through dedicated software. The corresponding parameters of the motor are then configured, and the corresponding input and output bytes are specified (e.g., specifying the bits corresponding to running, fault, and other signals). The communication rate is determined by the master station and can be automatically obtained after M102 is powered off and restarted. 2.2 Inverter Configuration We connect the inverter device to a separate PBIM to form a separate network, with a communication rate of up to 1.5Mbps, ensuring reliable and rapid inverter control. After adding the inverter's GSD file, ABB_DRVICES_RPBA can be seen in the corresponding slave station library. Figure 3 shows the inverter PROFIBUS_DP network configuration diagram. Similar to M102, the master station number here is 0, and the inverter station number starts from 001. Note the Modules and Ext. Prms in the network configuration. The inverter supports five PPO Modules, PPO1 through PPO5. Here, we choose PPO4, which can read more analog data but not inverter-related parameters. In the parameter settings, note that the Operation mode in the diagram should use the Vendor Specific protocol shown, not the default PROFIdrive protocol. On the inverter side, an RPBA module (ABB's dedicated PROFIBUS communication module) needs to be added. Its address is set via a hard jumper (must be the same as in the PKS). The corresponding communication parameters are then set in the inverter. Unlike M102, the inverter requires initialization (to complete the frequency conversion control function), which must be done in the DCS to ensure normal communication after power failure and restart. Figure 3 shows the inverter network configuration. The configuration process in the PKS system is completed using CONTROL BUILD. The PROFIBUS fieldbus communication and interlocking control are divided into four steps: (1) Establish the master communication station and add the function block PBIM BLOCK (see PBIM_SST in Figure 4). That is, add the "physical" communication module. (2) Add the virtual slave device block (see PBI_DEVICE and PROFIDRIVEDEV in Figure 4) to form a PROFIBUS communication network with the master communication station. That is, add the "virtual" communication module. (3) Add the input and output function blocks (see PBI_INCHAN and PBI_OUTCHAN in Figure 4) to correspond to the input and output addresses of the slave station. (4) Add PBI_INCHAN and PBI_OUTCHAN to the corresponding control module (CM) to complete the corresponding interlocking, control and other functions. Figure 4 PKS configuration flowchart Specific implementation steps 3.1 Add the "physical" module, that is, add the PBIM hardware device (PBIM_SST) in the CONTROL BUILD project. Similar to other hardware, the name, CNET network location, and rack location of each PBIM must be set. Since the PBIM is essentially a PROFIBUS master station, the addresses and names of each slave station on its network must be configured here; the virtual modules, input/output offsets, etc., of each slave station must also be configured, as shown in Figure 5. Figure 5 PBIM Parameter Settings 3.2 Adding "Virtual" Modules This involves adding the input and output I/O modules of each slave station to the project. Based on the actual situation, use the PBI_DEVICE function block for each M102 to create three types of modules: AI, DI, and DO, such as S_1_AI and S_1_DO. For S_1_AI, the corresponding PBIM name, station number, module number, input data format, and input data size (bytes) need to be set. For S_1_DO, the output data format and output data size need to be set. For the frequency converter, use the PROFIDRIVEDEV function block to create a module of type PPO4. 3.3 Implementing Various Interlocking Controls in the CM Each CM can support multiple function blocks, which are connected by arrow lines. CMs can also be interconnected to achieve more complex control. The CONTROL BUILD software also allows users to customize their own CM function blocks (this allows for the encapsulation of interlocking for a large number of identical devices). Figure 6 shows the CM interlocking function blocks of a frequency converter. PBIN and PBOUT in the figure are PROFIDRIVEIN and PROFIDRIVEOUT type function blocks, respectively. PBIN is the input function block, including the frequency converter's digital and analog input signals; PBOUT is the output function block, including digital and analog output signals, and the initialization command for the frequency converter (by assigning a value of 1142 to the CWRAW pin). Function block M4S_9ADC is an encapsulated CM block that internally performs the on/off interlocking control of the frequency converter (not discussed in detail here). Its pins SA, KM, MR, and C correspond to the frequency converter's remote, running, ready, and command status signals, respectively. The status of various signals and the correspondence between functional blocks can be clearly judged by the connections and colors, which is very convenient for configuration and debugging. Figure 6 CM Function Interlocking Diagram 4 Conclusion In the PKS system, the interlocking control of electrical equipment is completed through the PROFIBUS fieldbus, which not only greatly reduces the number of cables, but also provides operators with more stable and reliable signals. It is believed that with the efforts of many DCS and electrical manufacturers, this method will be widely promoted and applied in large and medium-sized enterprises. References: [1] PKS System Manual. Honeywell. [2] ABB Inverter Manual. ABB. [3] M102 Technical Data. ABB. [4] Yang Ning, Zhao Yugang. Distributed Control Systems and Fieldbus [M]. Beijing: Beijing University of Aeronautics and Astronautics Press.