Telecast Adder 161, Instruction Manual

Adder™ 161

Audio I/O Circuits, Audio Inputs

Audio inputs and outputs are on sixteen separate XLR connectors, each of which is

       connected to a circuit as shown in Figure 14.

Inputs can be set to have a balanced input impedance 600 or 10 K. 

The audio

       input circuit shown in Figure 14 can accept a wide range of signal levels. Refer to
       “Specifications”  for details.

+5

5 9 4 8 3 7 2 6 1

Data I/O

IN

OUT

-

-

+

+

10k

100k

.1

74HC14A

Data to
Multiplexer

+5

39k

10k

10k

39k

22pf

22pf

10k

10k

MAX909

+

-

Data to
Multiplexer

+5

-5

BAT54S

1

2

3

4 5

6

7

8

Figure 12. Digital Input Circuit (Connectors 1 and 2 only)

Digital I/O Circuits, Data Connectors 1 and 2

Digital I/O Circuits, Data Connectors 3 and 4

These connectors have contact and relay closure capability only. Digital data can only

       be accepted and sent on connectors 1 and 2. The contact input and relay output

circuits are as described above. The pin wiring for connector 3 and 4 closure circuits is

       the same as on connectors 1 and 2.

The TX digital input buffer circuit shown in Figure 12 accepts both data signals
(RS-232, RS-422 and RS-423) and contact closures and delivers this information to

       the multiplexer. The data handling portion of the circuit is connected only to DB-9
       subminiature data connectors 1 and 2.

It also accepts a contact closure indicated by the switching of pin 8 to ground level, pin

       3. This can also be accomplished by a TTL connection closure with pin 3 as the ground
       reference.

The RX digital output buffer circuit shown in Figure 13 accepts the demultiplexed data

       and contact closure signals and provides them at appropriate levels to the DB-9

subminiature data connector.

The output closure output is via an SPST-NO relay; this closure is not ground
referenced.

12