| element in a functional diagram at which variable quantities are added algebraically|
Note 1 to entry: In a functional diagram the summing point is primarily symbolized by a circle (see Figure 2).
Note 2 to entry: The algebraic sign is positioned at the right side of the incoming action line, seen in the direction of the arrow.
Note 3 to entry: This entry was numbered 351-23-06 in IEC 60050-351:2006.
Figure 2 – Functional diagram indicating typical elements of an elementary closed-loop control system