How does the Yokogawa DCS system communicate with the Siemens S7-300?
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This project plans to use the Yokogawa DCS system to communicate with Siemens PLC S7-300. The specific requirements are as follows: 1. The DCS should display the data from the secondary instruments connected to the PLC, such as temperature and pressure values. 2. DCS can control the start and stop of the pump driven by the PLC. What conditions are required to meet these two functional requirements? How many ways are there? Next, I would like to share my views and seek guidance from experts: Is it sufficient as long as the communication protocols between DCS and PLC are compatible? Is programming and setup complicated, and is there a limit to the data transmission distance? By the way, the PLC can be controlled via a host computer and a touch screen; now it needs to be connected to a DCS in order to achieve centralized control. Please ask the experts for advice; definitely don’t go under······
Hold on yourself first so it doesn’t sink····
1. There are generally two communication methods: Modbus and Profibus. However, the vast majority are Modbus. The Yokogawa DCS requires an ALR121 communication card, and its configuration is relatively simple ； The configuration of the CP340 or CP341 is relatively complex for Siemens. Communications are generally used to transmit data; if it is for starting and stopping equipment, hard wiring is the best approach. 2. For any protocol-based communication, both sides must be consistent. For standard Modbus cables, it is best to keep the distance within 500 meters; if the distance is greater, it is recommended to use fiber optics along with optoelectronic converters. Here at our site, a distance of 5000 meters is no problem at all. You already use touch screens and a host computer; so if DCS control is to be added, the logic will need to be modified as well. I’m not sure what model of CPU you have on site; if you have extra PROFIBUS ports, you can use a PROFIBUS-to-Modbus module, which is a more cost-effective option – it’s much cheaper than using CP modules.
Thank you, hard wiring is also used here. If hard wiring is not used, can data be written into it? Some of these use remote I/O nodes.