4) Hands-free Substation
Model (HF-620S/630S/631S/640S)
NP Type
Speaker volume switch
Microphone
Speaker
In-use lamp
Privacy switch
Dial keys
key
HF-620S
HF-630S
HF-631S
HF-640S
< Making a call >
1. Touching the key ma kes a call to the designated
other station whether the Privacy switch on your
station is in the ON position or OFF position.
2. Start conversation after the calling tone stops.
3. When the line is busy, a busy tone is heard and you
can camp on the line by simply waiting. As soon as
the l ine becomes free, your call is automatically
connected.
4. During a call attempt made by means of the continu-
ous calling tone, you can break in on the calling tone
by continuously depressing the key to make
a voice call through the station speaker of the called
party.
5. When the party you call is in a high noise level area,
your continuously depressing the key allows
one-way conversation to that party. As long as you
depress the key, your voice has dominance
and releasing the key will reverse the one-way
conversation from that party to you.
6. To terminate the conversation, depress the key.
< Responding to a ca ll >
[In the case that the Privacy switch is in the OFF
position.]
7. Respond to the call after the calling tone stops.
[In the case that the Privacy switch is in the ON posi-
tion.]
8. The continuous calling tone function is made avail-
able to any station when its Privacy switch is in the
ON position. Depressing the or key makes the
continuous calling tone stop and puts the station in
the conversation mode.
Note.
1. The sound volume o f the speaker may be adjusted by
means of the 2-stage volume selector (VOL ) switch.
2. The HF-640S is fitted with no Privacy switch, nor
key, nor key.

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