Section-j: mf-hf Equip. And Comms: Key Topic #90: mf-hf arq Operation - Answerbacks:

90J1 Which of the following events will take place immediately after phasing with a Coast Station on an available channel?

A. The ship station begins transmitting the text to the destination telex terminal.

B. The vessel will request the shore station's answerback to confirm it has reached the correct station.

C. The ship will transmit the desired command (such as DIRTLX+, OBS+ or AMV+) to the coast radio station.

D. After exchanging answer-backs (WRU/AAB) the coast station transmits GA+? and awaits a command.

90J2 During SITOR (NBDP) ARQ operations through a coast station, what should the GMDSS operator do during the "Automatic Exchange of Answerbacks"?

A. Do nothing other than wait for a GA+? prompt and then issue the desired command.

B. Send a "WRU" then a "Here is" when requested to do so by the coast station.

C. Send the necessary message file and then wait for time and charges.

D. Wait for the coast station to transmit a menu of possible commands and select the desired action.

90J3 Assuming sending a direct TELEX message to a shore-based office, which sequence of events best describes a complete ARQ TELEX exchange with a coast station?

A. Initiate call, observe phasing, wait for exchange of answer-backs (WRU-AAB), send message, send KKKK to terminate the TELEX link, receive MRN & time and charges.

B. Initiate call, observe phasing, wait for exchange of answer-backs (WRU-AAB), send DIRTLX command with zero, TELEX country code, TELEX number, send message, send KKKK to terminate the TELEX link, receive MRN and time and charges.

C. Initiate call, observe exchange of answer-backs (WRU-AAB), send message, send KKKK to terminate radio link, receive MRN & time and charges.

D. Initiate call, observe phasing, exchange of answer-backs (WRU-AAB), send message, send KKKK to terminate radio link, receive MRN & time and charges.

90J4 For ARQ communications with a Public Correspondence Coast Station, which sequence of events best describes reaching the point in time where the text of TELEX communications should be sent.

A. Transceiver setup, SELCAL selection, Initiate Call, wait for exchange of answer-backs (WRU-AAB), OPR+, operator entry of the appropriate automatic TELEX code.

B. Transceiver setup, wait for exchange of answer-backs (WRU-AAB), OPR+, operator entry of the appropriate automatic TELEX code.

C. Transceiver setup, SELCAL selection, Initiate Call, wait for exchange of answer-backs (WRU-AAB), GA+?, enter DIRTLX xy+, MOM, MSG+? and exchange of terminal answerbacks.

D. Transceiver setup, wait for exchange of answer-backs (WRU-AAB), GA+? and then send message text.

90J5 During ARQ communications, which of these is least likely to cause a coast station to immediately break the phased radio connection:

A. If the automatic exchange of answerbacks is interrupted by keyboard entries.

B. If the error percentage of repeat requests becomes too high.

C. If the operator enters "KKKK" at the end of the message.

D. If the BRK+? Command is transmitted after time and charges are received.

90J6 During ARQ communications, which of these is least likely to cause a coast station to break the phased radio connection:

A. If the error percentage of repeat requests becomes too high.

B. If the operator enters "BRK+".

C. If the automatic exchange of answerbacks is interrupted by keyboard entries.

D. If the operator enters "NNNN" at the end of the message.

Answers: 90J1 - D 90J2 - A 90J3 - B 90J4 - C 90J5 - C 90J6 - D