Abstract: A bus system for the serial transmission of digital data with a multiplicity of individual addressable bus transceivers (BT), which are connected by an only two-wire common bus, via which both synchronising signals and also digital data and energy are exchanged between the BTs. As the value of a bit, The result of an elementary logical operation (AND or OR) on the values of all simultaneously transmitting BTs with the same address is transmitted to all the receiving BTs with the same address simultaneously. Each BT includes its own time control and synchronising circuit with a time base, a bit counter, a byte counter and a comparator. With an identity between the imprinted address and that appearing on the bus a byte of digital data is transmitted serially via an I/O port The bus system can be put into operation and operated without the use of software, whereby polarisation errors in installation are excluded.

Abstract: A measuring battery clamp (1) with a fastening sleeve (2), with which it is firmly fixed to the positive pole connector (9) of a rechargeable battery (42) both thermally and electrically conducting, includes in its interior sensors (14, 21, 40), as well as means (16, 32, 33, 34) to process the signals generated by the sensors and to prepare them for passing on by means of a two-wire data line (13) to matching indicator units (28, 29). For the energy supply to the sensors (14, 21, 40) and to these means (16, 32, 33, 34), the measuring battery clamp (1) is also connected to the negative pole connector (47) of the battery (42) via a battery cable (12). With the smallest installation outlay it is possible to bring to display various quantities relating to the battery, such as temperature, voltage, current, power or ampere-hour count on indicator units (28, 29) as well as being used to optimize the battery use during charging and discharging.