Abstract: A flexible test arrangement for performing measurements on a test object. A plurality of safety components, each having a safety module which can be set to active or inactive, and having a ready status which can be set to active or inactive, is provided in a circular test arrangement. Each of the safety components carries out a number of function tests cyclically. As one of the function tests, a cyclical, error-free reception of a data packet is tested. One of the safety components is selected as a bus master which cyclically transmits a bus verification signal in a data packet to the safety component which is adjacent in the direction of transmission, wherein the bus verification signal is relayed by each of the safety components in a data packet, and, when said bus verification signal is received in a data packet, the bus master determines that the circular test arrangement is closed.

Abstract: A meter provides an arrangement for the optional connection of its voltage circuit to a current path or to a calibration system. The arrangement includes an opening, provided in the housing of the meter for inserting a contact device connected to the calibration system, and a pivoting lever. On insertion of the contact device into the opening, the pivoting lever can be moved from an operating position, connecting the voltage circuit to the current path, into a calibration position connecting the voltage circuit to the calibration system. Consequently, the arrangement can be changed over between the operating position and the calibration position with a minimum possible cost.

Abstract: The converter contains a number of electronic elements (3, 5, 7, 8, 9) and cooling elements (2), which are all mounted on a common holding plate (1) designed as a holding component. The holding plate (1) comprises the necessary electrical connections (10, 11, 14) and can be connected via plugs (10, 11, 14) to a base plate mounted in the corresponding device.Owing to this modular structure, the converter can easily be adapted to varying types of power without the need for structural modifications. The converter is economic to produce and to test and is also extremely convenient to use and to maintain.Also disclosed is ripple control transmitter apparatus in which such converters are used for frequency changing and are arranged for convenient use and good cooling.