Panasonic KX-TG4011N Service Manual page 17

Call Waiting Caller ID
Calling Identity Delivery on Call Waiting (CIDCW) is a CLASS service that allows a customer, while off-hook on an existing call,
to receive information about a calling party on a waited call. The transmission of the calling information takes place almost
immediately after the customer is alerted to the new call so he/she can use this information to decide whether to take the new
call.
Function:
The telephone exchange transmits or receives CAS and ACK signals through each voice RX/TX route. Then FSK data and
MARK data pass the following route.
Telephone Line → P101 → L101, L102 → C121, C122 → R121, R122 → IC501 (25, 24).
If the unit deems that a telephone connected in parallel is in use, ACK is not returned even if CAS is received, and the
information for the second and subsequent callers is not displayed on the portable handset display.
KX-TG4011N/KX-TG4012N/KX-TG4013N/KX-TGA402N
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