Today, we will discuss a topic that excites many industrial control enthusiasts – how the S7-1200 can create an industrial IoT gateway. Imagine being able to achieve remote monitoring and intelligent management of devices with a small PLC; doesn’t that sound cool? Let’s unveil this technology together! 1. What is the S7-1200 Industrial Gateway? The … Read more
The communication routine for Schneider PLC involves three function blocks: ADDM, READ_VAR, and WRITE_VAR. Below, I will introduce each of them. 1 ADDM The ADDM function block is for address conversion, which converts the physical address of the PLC into an address type recognizable by the PLC. To put it simply, it converts a string … Read more
1. What is MODBUS?1. Basic Concept MODBUS is a soft communication protocol first advocated by MODICON (now a brand of Schneider Electric), which has gradually been recognized as a standard communication protocol through practical applications by most companies. As long as data communication or transmission follows this protocol, different systems can communicate with each other. … Read more
Debugging Techniques for PLC and Inverters In industrial automation, the combination of PLC (Programmable Logic Controller) and inverters is widely applied. The PLC is responsible for controlling the inverter’s start, stop, acceleration, deceleration, and frequency adjustment to achieve precise control objectives. By employing reasonable debugging techniques, the stability and reliability of the system can be … Read more
(Click the above brown words to download the materials) Consider a DC power supply with three pins at its output socket: positive, negative, and ground. Accordingly, the load’s plug should also have three pins corresponding to the power supply side to correctly obtain the energy supply. Note that there are three essential conditions to be … Read more
Common Issues 1. Does S7-200 SMART support Modbus ASCII communication mode? The STEP 7-Micro/WIN SMART software does not provide a command library for Modbus ASCII communication mode. If the S7-200 SMART CPU is used for Modbus ASCII communication, the user needs to program using the free port communication mode. 2. Can the integrated RS485 port … Read more
The Modbus protocol is a widely used communication protocol specification and is one of the earliest protocols applied in industrial fields. Since the emergence of industrial serial links in 1979, the application of Modbus has become common, enabling communication between various automation devices. Friends engaged in embedded product development should be familiar with it, as … Read more
1. Hardware Setup The Modbus communication in the program is conducted between the communication port 0 of two S7-200 CPUs (it is best for each CPU to have two communication ports). On the master side, you can also use the corresponding library files “MBUS_CTRL_P1” and “MBUS_MSG_P1” to communicate through communication port 1. Communication port 1 … Read more
Click on “Benefits Are Here! Free PLC Resources, Do You Want It?“ 1.What Are the Differences Between ModBus RTU and ModBus Communication Protocol? ModBus protocol is an application layer message transmission protocol (OSI model layer 7), which defines a protocol data unit (PDU) independent of the communication layer, that is, PDU=Function Code+Data Field. ModBus protocol … Read more
This article introduces: the MODBUS TCP client communication program for Siemens S7-1200 PLC. Step One:Create a DB block named:MODBUS_DB Step Two:Create a variable:Mod with data type:TCON_IP_v4 Step Three:Set the hardware identifier:16#40; ID:10 (can be changed);ConnectionType16#0B;ActiveEstablished( Client1 (Active): Server is0 (Passive)): Set toTRUE Step Four:Set theIP address (ADDR): 192.168.1.245 Port number 502 Step Five:Create a MODBUS … Read more