EFJohnson 3000 SERIES Manuale Utente

13-2

13.2.1 SNM SWITCH SETTINGS

See Figure 13-2 for Alignment Points Diagram.

Command and Control Communication

The command and control communication is by 

blank and burst signaling using Audio Frequency Shift 
Keyed data on the Main audio lines.

13.2.2 AFSK COMMUNICATION ON THE MAIN 

LINES

13.2.3 SNM JUMPER PLACEMENT

13.2.4 SNM BACKPLANE EXTERNAL CON-

TACTS

See the Backplane Section 23 for pinouts on the 

shelf backplane and wire harness pinouts.

13.3.1 PRE-ALIGNMENT

The SNM is pre-aligned with the Basic Board 

Module alignment procedures; refer to Section 7.3.

13.3.2 SNM ALIGNMENT PROCEDURE

Connections to the SNM may take several forms:

1. Direct Connection

2. Leased Lines

3. Microwave Link

4. T1 Channel Bank Interfaces

This ancillary equipment requires certain input 

and output levels for proper operation. The module 
should be adjusted accordingly.

1
1
1
-

-
2
2
-

-
3
3
-

4
4
4
-

-
-
-
1

2
-
-
2

3
-
-
3

-
-
-
4

J24

1 to 2*
2 to 3

Selects 27512 EPROM operation
Selects 27256 EPROM operation

J27

1 to 2
2 to 3*

Not used
Normal operation

P33

1 to 2
3 to 4
5 and 6

Jumpered
Jumpered
open

J36

1 only
1 to 2
2 to 3

Not used
-48V E-lead operation
-15V E-lead operation

J14
J15
J21
J22

Jumper pin 1 to 2 for high impedance ground path 
for split 600 ohm inputs and outputs.  Leave open if 
no ground path desired.

* Indicates normal operation.

pin 27
pin 28
pin 29
pin 30
pin 31
pin 32

Sec Rx +
Sec Rx -
EA lead
EB lead
Pri Rx Audio+
Pri Rx Audio-

pin 1
pin 2
pin 3
pin 4
pin 5
pin 6

RxS+
RxS-
EA
EB
RxA+
RxA-

pin 59
pin 60
pin 61
pin 62
pin 63
pin 64

Sec Tx +
Sec Tx -
MA lead
MB lead
Pri Tx Audio+
Pri Tx Audio-

TxS+
TxS-
MA
MB
TxA+
TxA-

pin 1
pin 2
pin 3
pin 4
pin 5
pin 6