EFJohnson 3000 SERIES Manuale Utente

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SYSTEM NETWORK MODULE (SNM)
13-4
Main Transmit
1. Determine the maximum level to be received by the 
ancillary equipment to be transmitted.
2. Set S5 for Test 1 (open section 1, close sections 2, 3 
and 4).
3. Reset the module, Press S2 and release.
4. Adjust R44 for -12 dB from the maximum level in 
Step 1 at J12.
5. Set S5 for Test 8 (open section 4, close 1, 2 and 3).
6. Reset the module, Press S2 and release.
7. Adjust R86 to be -12 dBm 
±
0.5 dB at TP4.
8. Verify the level at J12 to be -21 dB 
±
1 dB from the 
maximum level from Step 1.
9. Select for normal operation (S5 all sections closed).
10.Reset the module, Press S2 and release.
Example:  Microwave has -16 dBm max input, set 
J12 for -28 dBm.
Main Receive
1. Determine the maximum transmit level that is sent 
by the ancillary equipment to the interface module.
2. Set S5 for Test 1 (open section 1, close sections 2, 3 
and 4).
3. Reset the module, Press S2 and release.
4. Insert the maximum level determined in Step 1 
using a 600 ohm audio oscillator into EQU port of 
J1.  Otherwise, set the ancillary equipment to send 
the alignment tone to the interface module.
5. Adjust R41 to be -6 dBm at J11.
6. Close section 2 of S1.
7. Adjust R102 to be 0 dBm at TP8.
8. Set S5 for normal operation (all sections closed).
9. Reset the module, Press S2 and release.
Example: Microwave has +7 dBm maximum 
output, set J11 for -5 dBm.
Secondary Transmit and Receive
Not used since the secondary line is not used.
Figure 13-3   SNM CABLE LAYOUT
NOTE: This cabling is used within a single Switch or between Switches to allow Unique ID calls to occur.
EA
EB
MA
MB
RXA+
RXA-
TXA+
TXA-
EA
EB
MA
MB
RXA+
RXA-
TXA+
TXA-
SNM
SNM