User manual

2-6 P1200A User Manual
INPUT B
INPUT LINK
INPUT A
INPUT LINK
P1200A input signal connectors
-transformer balanced input
option fitted
INPUT B
INPUT LINK
INPUT A
INPUT LINK
MONO OUT
P1200A input signal connectors
Pin assignment for remote
control
Pin 3 (+)
Pin 1 (–)
Pin 1 (GND)
Pin 2 (pos. signal)
Pin 3 (neg. signal)
Pin assignments on P1200A signal inputs
2.8. Connections
INPUTS A/B and INPUT LINK
Each of the two mainframe channels has its own 3 pin XLR female
input connector. Below and wired in parallel with each input
connector is a 3 pin male XLR input link connector used to feed the
input signal on to the next device in the system signal chain.
INPUT A relates to the left hand controller module, INPUT B to the
right hand module (front view).
MONO OUT
In a P1200A, the two input signals of INPUT A and INPUT B are
combined, electronically balanced and buffered. This signal is then
routed to the rear panel MONO OUT connector.
The signal level at the MONO OUT connector is -3 dB the sum of
the mainframe controller module inputs. The 3 dB signal
attenuation prevents feedback if the signal routing is incorrect (e.g.
if the MONO OUT is routed to a module signal input in the same
mainframe).
The MONO OUT signal pins (2 and 3) are disconnected by a relay
when the mainframe is powered off. To prevent disruptive noises
when switching on the mainframe they are connected after a short
delay.
For further information see also section 5.3. (Using the P1200A
MONO OUT).
Transformer balanced input (option)
To prevent system ground loops, the P1200A can be supplied with
transformer balanced inputs. The transformers used are studio
quality torroidal transformers able to handle signal levels up to
+28 dBu without degrading the systems low frequency response.
The input balancing transformer gives electrical isolation between
the source output (e.g. mixing console) and controller inputs and
therefore prevents ground loops. A 22 kohms coupling resistor
prevents electrostatic loading of the mainframe.
The P1200A when fitted with input transformers loses the MONO
OUT facility.
REMOTE CONTROL
The P1200A is fitted with a two-wire serial remote control
interface. The 3 pin female DIN remote control connector is located
on the left of the P1200A rear panel. The connector is opto-
coupled.
The remote functions are detailed in section 2.6. (Remote control &
monitoring).