HART中的Burst-Mode(突发模式)

突发模式是高速的数据传输模式,其模式通常有几个数据源。在数据总线中,突发模式通常变为专为满足一个设备的通道。

 

辅助材料1:

Burst-Mode is optional for a HART products but is strongly recommended.

HART Burst-Mode supports the publishing of cyclical process data using "Burst" messaging. In this mode, a device is instructed to publish the response to a command continuously without any further Master or Host action.

If a Field Device supports Burst-Mode then all of Commands 103-105 and Commands 107-109 must be implemented. Furthermore, devices implementing Burst-Mode must support at least 3 Burst Messages. Existing, legacy Field Devices updated from HART 5 are allowed to support only one Burst Message.

 

辅助材料2:(https://www.crifan.com/comparation_among_hart5_hart6_hart7/

HART7相对于HART5(和HART6)的功能上,主要增加了:

(1)Enhanced Burst Mode

增强的突发传送模式

更适用于高速的无线(wireless)传输,因为其速度是250Kbit/s,而相对有线的(wired)传输速度是1.2kbit/s。

所以,对于有线的,双线回路(two-wired loop)来说,因其必须工作在小于4mA的环境下,更推荐使用HART5的查询(Polling)模式用于诊断信息(diagnositics)。

而对于4-20mA的设备来说,HART5,也已经够用了。

posted @ 2020-01-04 17:18  心媛意码  阅读(1537)  评论(0编辑  收藏  举报