14 Installation
C-2000 and C-2000HS Technical Manual
Bosch Security Systems, Inc.
Technical Manual
F.01U.174.927 Rev 03
TX Side Settings
The C-2000 TX output circuitry has a
DPDT
(Double Pole Double Throw) relay that is used to connect and disconnect the TX
output transformer from the TX line based on PTT status. This allows a very large number of consoles to be attached to the
line in parallel, because only the transmitting unit is directly connected to the line. When not transmitting, the
DPDT relay is connected to 600 Ohms or open circuit depending on the number of consoles connected in parallel to the line.
If only one (1) console is attached, this unit should have J12 in the A position. This makes it the effective master and
terminates the line with 600 Ohms. If multiple consoles are connected in parallel, one (1) console should be designated as the
master by placing J12 in the A position. The remaining consoles should be designated as slaves and should have J12 placed in
the B position. In this manner, the impedance looking back into the parallel configuration of consoles is still 600 Ohms.
Figure 7 shows the basic configuration.
NOTE:
•
The C-1616 could also be the master in this configuration.
•
If any of the consoles connected in parallel are not C-2000’s, then all the C-2000’s should be configured
as slaves. Additionally, J14 should be used as a TX line impedance correction if there are consoles other
than the C-2000 connected in parallel. J14 position B adds another 600 Ohms to the output TX line. J14
Position A is straight through.
Transmit Monitor
In a 4-wire system with parallel consoles, the transmit line may be monitored. The
Transmit Monitor
is not needed in 2-wire
mode because transmit audio is already on the receive circuit. The transmit monitor, in 4-wire mode, is used to detect transmit
activity for the TX Detect LED. For more information, see “Transmit Monitor Setup” on page 15.
Level Adjustments
Transmit Side Adjustments
The transmit audio consists of multiple audio sources, microphone audio, AUX input, Function Tones, and
DTMF
(Dual Tone Multiple Frequencies) tones. Each audio source is summed or generated in the
DSP
(Digital Signal Processing) with the analog signal being generated on a single DAC. The following is a list of the
potentiometers that affect the transmit path.
Reference Description
R171
TX Output Level Adjustment
R105
Desk Microphone Adjustment
R115
Handset Microphone Adjustment
FIGURE 7.
Master and Slave Console Configuration
