BS ISO 9876:2015 pdf download – Ships and marine technology — Marine facsimile receivers for meteorological charts.
3.5 IOC selection signal signal for automatic IOC selection in the facsimile receiver which is accomplished by transmission of alternating black and white signals lasting for 5 s to 10 s with the following frequencies: — 300 Hz for IOC 576; — 675 Hz for IOC 288 (or IOC 576 with alternate line scanning). Note 1 to entry: The envelopes of the signal are approximately rectangular. 3.6 meteorological chart chart portraying the state of the weather (such as weather conditions, wind force and direction, high or low atmospheric pressure, weather front and isobar) at a particular time over a wide area 3.7 phasing adjusting the phase of the independent synchronous power source so as to be able to receive the weather chart in its correct position 3.8 phasing signal signal for automatically phasing the facsimile receiver accomplished by a 30 s transmission of alternating black and white signals with the following frequencies: — 1 Hz for 60 lines per minute (60 r/min); — 1,5 Hz for 90 lines per minute (90 r/min); — 2 Hz for 120 lines per minutes (120 r/min). Note 1 to entry: This signal may also be used for automatic starting, automatic selection of scanning frequency, and automatic adjustment of recording levels. Note 2 to entry: The wave form of this signal is either symmetrical, i.e. black and white, each lasting half the scanning line, or symmetrical with the white lasting for 5 % and black for 95 % of the scanning line. 3.9 remote control signal control signal for operating the apparatus from a distance Note 1 to entry: The remote control signals for operating the facsimile receiver for meteorological charts include the phasing signal, the IOC selection signal, and stop signal. 3.10 SND/N value of signal plus noise plus distortion to noise ratio
4 Requirements 4.1 Construction 4.1.1 The equipment shall comprise of a radio receiver and a recording unit. 4.1.2 The recording unit shall be constructed as to allow for the change of recording paper and either or both recording stylus during day and subdued artificial light. It should be possible to affect routine maintenance under the same conditions. 4.2 Performance standards for recording unit 4.2.1 Recording unit The equipment shall be capable of continuous recording while transmissions are being received. 4.2.2 Input signals The recording unit shall accept input signals from an external receiver in the audio frequency range at an input level of at least –10 dBm to +10 dBm and shifts of ±150 Hz and/or ±400 Hz about a centre frequency of 1 900 Hz at an impedance of 600 Ω. 4.2.3 Index of cooperation (IOC) Automatic or manual operation at an index of cooperation of 576 and 288 shall be possible. 4.2.4 Scanning speeds The recording unit shall be capable of the automatic and manual selection of scanning speeds of 60, 90 and 120 scans per minute.