DIN ISO 22090-2:2015-11

The three standards of the DIN ISO 22090 series apply to transmitting heading devices (THD). This electronic device provides information on the true heading, which is the angle between the keel line of a ship and true north. The mode of operation of a THD is usually based on one of three different procedures, for which the relevant requirements and tests are defined in the respective part of DIN ISO 22090. This part (2) of DIN ISO 22090 applies to THDs operating with a magnetic compass (geomagnetic principles). The revision was necessary for the following reasons: 1) The new standard from the IEC 61924 series with requirements and tests for the integrated navigation system (INS) had to be taken into consideration. 2) Three new or amended resolutions of the IMO (International Maritime Organisation) also had to be considered. These contain performance requirements for - the transmitting heading device (THD) itself; - the communication of alert signals in connection with the integrated navigation system (INS); - bridge alert management (BAM). The specifications contained in the regulations and standards have been implemented to specify requirements for issuing alerts in the event of malfunction of the transmitting heading device or its power supply. In addition, using the aforementioned new IEC standard for integrated navigation systems, the requirements for communication between the transmitting heading device and the integrated navigation system have been defined for - the alert signals; that is, the standardized data words to be used by the transmitting heading device and - the device itself (the alert communications interface), which transmits the digital alert signal from the THD to the INS/BAM, and - the testing of this interface device. In addition, following the amendments in the aforementioned IMO resolutions, the term "alarm" has been replaced by the term "alert", because consistent compliance with the regulations and standards mentioned here means that any errors that may occur are reported and prioritised early enough so that countermeasures may be taken and there is no need to fear immediate danger to the ship.