44124-0798 <90-00024>
P
AGE
3
F
IG
. 1 - E
XAMPLE
A
PPLICATION
, 44124
APPLICATION INFORMATION
CIRCUIT DESCRIPTION
A
functional schematic for the 44124 Data Channel Termina-
tion Module is shown in Fig. 2. Here is a brief description of
each of the functional parts of the circuit:
Impedance Matching Transformers
Two of the impedance matching transformers (T1 and T3)
provide a switch selectable impedance of 150, 600, or 1200 ohms
(set with switch 6). The module line conditioning circuit couples
the line side receive and trasmit signals.
The drop side transformers provide a switch selectable applica-
tion of two-wire or four-wire lines (select with switch S10). Drop
side transformer impedance is fixed at 600 ohms.
Input Equalizer Circuit
The input equalizer circuit receives an incoming signal from the
impedance matching transformer (T1). The circuit adjusts slope,
bandwidth, and amplitude before the signal reaches the input
amplifier.
Set slope equalization with switches S8-1 to S8-5
♦
Switch S8-1 sets the equalizer slope cable to loaded or
nonloaded.
♦
Switches S8-2 to S8-5 have assigned values that determines
the total slope figure.
46020-XX
MAP
46023-1X
SMART MAC
46033-XX
ESA
44124-XX
DST
46020-XX
MAP
46023-1X
SMART MAC
460 ALARM AND CONTROL SYSTEM
DATA / TTL
1
8
RS-232
SUBASSEMBLY
EIGHT
RS-422
SERIAL PORT
DCP
TABS
MASTER
PORT
PRINTER
PORT
202 MODEM
SUBASSEMBLY
XMT OUT
RCV IN
DATA / TTL
1
8
RS-232
SUBASSEMBLY
EIGHT
RS-422
SERIAL PORT
DCP
TABS
MASTER
PORT
PRINTER
PORT
LOOPBACK
DETECT
LOOPBACK
DETECT
600
Ω
600
Ω
XMT IN
600
Ω
RCV OUT
600
Ω
RS-232
PORT
TO
FMAC
NMA
TASC
ETC...
LINE
SIDE