18
TASCAM AV-452
Installation & Support Guide
7 – External control
The AV-452 can be controlled from other units in two
ways.
The first is a serial protocol, as used by many AV
controller vendors. This allows a number of AV-452
units to be controlled from a personal computer, as
well as by these dedicated controllers.
The second is by using the relay connector, allowing
a number of external relay controls and tally indica-
tors to be connected to the AV-452.
AV-452 serial protocol
NOTE
A separate document “AV-452 Serial Control Protocol”,
providing details on the implementation of the serial
control, is available on request from your TASCAM
dealer or distributor. If you are implementing the serial
protocol, you may choose to provide your “back-room”
systems integration team with the separate document,
and to keep a copy to hand for troubleshooting on site.
The serial port can operate as a RS-232, RS-422 or
RS-485 port (as determined by the controller or
PC).The AV-452 is fitted with a standard 9-pin D-sub
serial port, as well as a rotary address selector switch
h
, allowing it to take an ID from 0 through 9.
This allows a number of AV-452 units to be chained
together and controlled from a single source.
NOTE
Only set the serial address with the power to the AV-452
turned off as the AV-452 will only recognize the setting
at power-on.
Serial port pinouts
The diagrams above show the AV-452 rear panel con-
nector. Any cable connectors will accordingly be
mirror images of the above.
The transmission speed is always 9,600 bps, with a
character length of 8 bits, and no parity. The com-
mand spacing is >25 ms.
The RS-422 and RS-485 implementations follow
standard specifications.
The RS-232 operation is a modification of the RS-
422 port, operating at 0 to 4.5 V, rather than ±9 V. It
should work with most older control systems and
PCs, but if you have problems with using this proto-
col, try using the controller with RS-422, if possible,
to remedy the situation.
Relay control port
There is also a 37-pin D-sub connector
g
which may
be used for relay control of the AV-452 and connect-
ing tally indicators.
The following should be taken into account when
connecting external equipment to the AV-452 using
this port:
The relay outputs are low when active, and must be
low for at least 50 ms.
The maximum current is 20 mA, and the maximum
voltage is 30 V.
The tally indicator outputs are open collector.
RS-232
RS-422
RS-485
Pin 2: Rx- Data
Pin 3: TX- Data
Pin 5: Ground
Pin 2: Rx- Data
Pin 3: Tx- Data
Pin 5: Ground
Pin 6: Rx+ Data
Pin 7: Tx+ Data
Pin 2: TxRx- Data
Pin 3: TxRx- Data
Pin 5: Ground
Pin 6: TxRx+ Data
Pin 7: TxRx + Data
GND
Rx-
Tx-
GND
Rx-
Tx-
Rx+
Tx+
GND
TxRx-
TxRx+