公开(公告)号：US07835125B2

公开(公告)日：2010-11-16

申请号：US11753151

申请日：2007-05-24

申请人： Ewald Freiburger ,  Jürgen Briggmann

发明人： Ewald Freiburger ,  Jürgen Briggmann

IPC分类号： H02H7/00

CPC分类号： G05B19/0425 ,  G05B2219/25428

摘要： In a circuit for safe forwarding of a physical or technical variable between at least two systems in communication with one another, which variable is represented by the value of a loop current (Is), which is adjusted by a control unit (11) by means of a current output circuit (13) in a current loop (20, 60), the current output circuit (13) has at least two parallel-connected final control elements (131, 132), controllable by the control circuit (11), as current sources for mutually independent adjustment of a value of the loop current (Is). The final control elements (131, 132) are in series with at least two likewise series-connected measurement resistors (133a, 133b). The voltage, proportional to the loop current (Is), dropping via at least one but not all of the at least two measurement resistors is fed back to the control unit (11), which compares the value of this voltage with the corresponding value of the loop current, which value is specified to at least one of the final control elements, and in the event of deviations, via a predeterminable threshold, allocates an fault value corresponding to the NAMUR recommendation NE043 to the loop current via the first final control element (131), and in the case of failure of the first final control element (131) via the second final control element (132). A monitoring circuit (17) is provided, which in the event of failure of the control unit (11) allocates an fault value that likewise corresponds to the NAMUR recommendation NE043 to the loop current via the second final control element (132).

摘要翻译： 在用于在彼此通信的至少两个系统之间安全转发物理或技术变量的电路中，哪个变量由循环电流（Is）的值表示，该电流由控制单元（11）通过装置 在电流回路（20,60）中的电流输出电路（13）中，电流输出电路（13）具有可由控制电路（11）控制的至少两个并联的最终控制元件（131,132） 作为相互独立调整回路电流（Is）值的电流源。 最终控制元件（131,132）与至少两个同样串联连接的测量电阻器（133a，133b）串联。 与环路电流（Is）成比例的电压通过至少一个但不是全部的至少两个测量电阻器下降到控制单元（11），控制单元（11）将该电压的值与 循环电流，该值被指定到最终控制元件中的至少一个，并且在偏差的情况下，经由可预定阈值，经由第一最终控制元件将对应于NAMUR推荐NE043的故障值分配给回路电流 （131），并且在第一最终控制元件（131）经由第二最终控制元件（132）发生故障的情况下。 提供了一种监视电路（17），其在控制单元（11）发生故障的情况下，经由第二最终控制元件（132）将类似于NAMUR推荐NE043的故障值分配给回路电流。