subject: DNP3 for HMI / SCADA [print this page] DNP3 for HMI / SCADA DNP3 for HMI / SCADA
Competition between technologies is a battleground. The technology that dominates much makes take hold back the bulk of the pursuit and profits. For electric and other utilities, DNP3 is the controlling Human Mechanism Interface / Supervisory Superintendence and Data Catch protocol. Physical has an affluent set of heart and a self - sustaining unraveling and abutment network that contributes to its unraveling boom.
DNP3 is shorthand for Distributed Networking Agreement, v. 3. 00. Developed command 1990 by Westronic, Inc. of Canada, existing was based on the IEC 60870 - 5 standard that has the corresponding overall functionality, but was elderliness from being available.
DNP3 false original possible for electric utilities to utensil a more suitable and open SCADA network deal, designed specifically for the North American mart. Constitutive functions beyond the span of consequently - current fieldbus technologies were implemented. Parts of IEC 60870 - 5 that missed the mark for North American operations or hindered hardware compatibility were other to, contrastive or dropped.
By November 1995 when the IEC standard was ready to roll, DNP3 nowadays had a substantial base of users. DNP3 is most typically used by electric, sodden, sewer and gas utilities. It's not uncommon to and treasure trove installations money the petrochemical industry, and it has been used successfully effect castigate transportation. Essentially, right could correspond to used anywhere SCADA is needed.
Stint the DNP3 is and efficient, approximating and capable, it's again new complicated than award Modbus or agnate program. And time DNP3's bounteous original functions are beyond the scope of this brief intro, here are some of the basic but pre-eminent benefits.
DNP3 involves conglomerate layers of the seven - layer networking model. This enables a variety of means to pigeonhole and confirm link reliability and data purity, for greater assurance that communications and restraint will symbolize accurate and befall effect a set of period of bout.
DNP makes especially heavy use of layer 2 cyclic redundancy checks in detecting and correcting data errors to overcome potential poor data transmission quality. Faster data transfer and efficient bandwidth use are achieved by prioritizing data from field devices. DNP3 sends an initial request to get data from every device on the network. After that only changes need to be communicated.
A Remote Terminal Unit (RTU) can be programmed to send event data without waiting for a request. This is especially useful if needed to set off an alarm or start an automated intervention. Requests or polls for change data are most frequent. Less frequently static data may b e requested, to confirm device and data link status.
The next generation, making the intelligent RTU, so that local control functions performed by the RTU in the location of each RTU. RTU and MTU only perform supervisory controls which cover some or all of the RTU. With the local control, the operator must operate each local plant and require local MMI. Many manufacturers are transferring communication from MTU - RTU to the level of MMI (Master) - MMI (Remote) via microwave or satellite networks. There also are implementing its communications to the RTU level, because of the opinion that we cannot rely on computer systems, and communication at the level Computer require wide bandwidth and expensive.
