Spectracom 8194B, Инструкция по эксплуатации

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8194B, 8195B, 8197B Spectracom Corporation
GPS Ageless Master Oscillator Instruction Manual 5-14
5.7.3 RS-485 Timing Signals
The Data Sync timing signals are output in RS-485 levels. RS-485 is a balanced
differential transmission requiring twisted pair cable. Cable lengths up to 4000 feet are
possible when using cables specifically designed for RS-485 applications, like Belden
9844 or equivalent. These cables have a braided shield, nominal impedance of 120
ohms, and a capacitance of 12 to 15 Pico farads per foot. Refer to Figure 5-5 for a
schematic representation of an RS-485 line driver. Relative to RS-485 specifications
the A Terminal (-) is negative with respect to the B Terminal (+) for a Binary 1. The A
Terminal (-) is positive to the B Terminal for a Binary 0.
B
A
+
-
RS-485 OUTPUT
Figure 5-5 Data Sync Drivers
5.7.4 RS-232 CTCSS Configuration
The CTCSS outputs are configured using the front panel RS-232 COM port. The
C
TCSS
T
one
C
ontrol command, CTC, is used to read or set the configuration or
provide a listing of all CTCSS frequencies available.
In the following command descriptions, characters in
Bold Italics
are keys typed by the
user. Terminate all command lines with the enter key. The enter key is represented by
<ent>
. The responses from the unit are shown in
Italics
. Configure the terminal for
ANSI, 9600 baud, and xon/xoff flow control. The character structure is ASCII, 1 start, 8
data, 1 stop and no parity.
To retrieve the current CTCSS output configuration, issue the
CTC
command as shown
below:
Type:
CTC <ent>
Response:
CTCSS GENERATOR SETTINGS
1= XZ (67.00Hz) 2= XZ (67.00Hz) 3= NOT PRESENT 4= NOT PRESENT
To configure the CTCSS outputs, the unit must first be placed in
Set Mode
. Issue the
CTC
command followed by the CTCSS generator number and corresponding time
code. The
CTC
command structure is shown below:
Type:
CTC # xx <ent>
Where: # = CTCSS generator number, 1 or 2 (Option 17 adds 3 and 4)
xx = Two digit code corresponding to a CTCSS tone frequency.
Refer to Table 5-5 for code listings.