Panasonic KX-TD500 System Reference Manual page 37

E. System Configuration
1.00 Basic Shelf
Basic Shelf is always required.
Basic Shelf contains its own power supply and 14
mounting spaces called "Slot". CPU card and
TSW card are installed at factory.
The remaining 12 slots provide mounting space
for the various cards that can be used. Any
optional service card can be mounted in any of
these 12 slots.
So these slots are called "Free Slot".
Free Slot can be equipped with the following optional
service cards.
a. Loop start central office trunk (LCOT) Card
b. Loop start central office trunk with Pay-Tone
Detection (PCOT) Card
c. Loop start central office trunk with Polarity
Reversal Detection (RCOT) Card
d. Ground start central office trunk (GCOT) Card
e. Hybrid line circuit (HLC) Card
f. Digital hybrid line circuit (DHLC) Card
g. Proprietary ITS line circuit (PLC) Card
h. Digital proprietary ITS line circuit (DLC) Card
i. Single line telephone line circuit (SLC) Card
j. Single line telephone line circuit with Message
Waiting (MSLC) Card
k. Enlarged single line telephone line circuit with
Message Waiting (ESLC) Card
l. Direct inward dialing trunk (DID) Card
m. Off premise extension trunk (OPX) Card
n. Doorphone circuit (DPH) Card
o. Automatic Gain control (AGC) Card
p. Direct inward system access (DISA) Card
q. Remote circuit (RMT) Card
Basic Shelf consists of the followings.
No.
1 POWER-for Power Unit
2 BS1 (Basic Slot 1) - for CPU card
3 BS2 (Basic Slot 2) - for T-SW card
4 FS1 to 12 (Free Slot 1 to 12)
Construction of Basic Shelf
P F F F
O S S S
W 1 2 3
E
R
r. Attendant console Line circuit (ATLC) Card
s. E&M Card
t. T-1 Card (Free Slot 1, 5 or 9 only)
u. E-1 Card (Free Slot 1, 5 or 9 only)
1-E-1
Name
- for optional service card
F F F F F F
S S S S S S S
4 5 6 7 8 9 10
Number
1
1
1
12
F F F B B
S S S S
11 12 1 2