Oilfield Union Station has the following characteristics:

a. The overall system is large, and there are many local job systems, including stabilization posts, unit measurement posts, inventory storage system posts, sewage treatment system posts, filter tank system posts, dirty oil recovery system posts, fire protection system posts, boiler system posts, etc. And some posts are even a few hundred meters away from the monitoring center.

b. Some posts have very high requirements on system security and are suitable for independent and safe operation, such as stable post system. In view of this, it is not suitable to use a CPU control system for the entire joint station system, which is difficult to maintain in the later period and the system security is not high. Therefore, it is suitable to use a multi-substation system for independent and safe operation. When performing system maintenance on an independent substation in the later period, it will not affect the operation of other systems.

c. The data collected by some post systems is huge. For example, in some posts, there are many 485 instruments such as multi-function meters, etc. In view of the fact that Profibus single substation can only transmit 244 bytes of data with the main station, such a post will have to be split into multiple Profibus substations, so this type of Post is not suitable for Profibus distributed IO structure. It is understood that substations like Siemens ET200 can no longer add an independent CPU to independently control this substation (even if it can, the control scale is very small).

Oilfield Union Station Scheme

After a period of understanding of the overall operation rules of the joint station, I also learned the control system plan of the Qingdong Five Joint Station, which has just been put into operation this year, and combined with the characteristics of the NA400 PLC, we now give the overall plan of the control system suitable for the operation of the joint station. The feature is that the main station and the sub-station adopt the internal Ethernet communication scheme. The sub-station can operate independently, and it is divided into two schemes: single network and dual network.

1. Single network structure plan of one main station + multiple substations:

Features: Each substation PLC is equipped with a single-network CPU (CPU401-0301), and the Ethernet port on the CPU is connected by a network cable or optical cable, and a star connection is assembled at the multi-port switch of the main station cabinet. The main station is equipped with a PLC Ethernet master module (CMM401-0205), which is connected to the substation. The Ethernet port of the Ethernet module is directly connected to the switch through a super five twisted pair cable.

2. The dual network structure scheme of one main station + multi-substation:

Features: The PLC of each substation is equipped with a dual-network CPU (CPU401-0401), and the two Ethernet ports on the CPU are connected by two network cables or optical cables, and are integrated into a star connection at the two multi-port switches of the main station cabinet. . The main station is equipped with a PLC Ethernet master module (CMM401-0205), and the 2 network ports of the Ethernet module are directly connected to the above 2 switches through super five twisted pairs.