7
RS232 Connection
The RS232 connection is used to control the GRS44 by an external controller or
computer and can work with our without keypads. The GRS44 connects to the RS232
controller with a 9-pin db9 connector. The programming reference follows.
1.0 Terminal Settings
To control the GRS44 amplifier via other control systems, connect a RS-232 cable to the serial
control connector on the rear of the GRS44
and set your computer’s or control unit port settings
to match the following configuration:
SETTING
VALUE
Bits per second
19,200
Data bits
8
Parity
None
Stop bits
1
Flow control
None
Emulation
Auto detect
1.1 Command Summary
All commands are enclosed in parentheses. The request can be in some cases a read request
(followed by a “?”), or a write request (followed by 0-2 ASCII digits). A read command will return
the current setting, and write command will change the setting.
Read request format: (nAA?) where:
(
starts the command
n
denotes amplifier channel (if required)
AA
denotes the command (may be 1 or 2 letters)
?
denotes the read request
)
ends the command
Read Request Example 1.1:
Function
Command
Response
Volume
(1vl?)
returns the volume on channel 1 (0-87)
Write request format (nAA$$) where:
(
starts the command
n
denotes the amplifier channel (if required)
AA
denotes the command
(may be 1, 2 or 3 letters !!)
$$
denotes the value to be written if required (leading zero’s ARE necessary)
)
ends the command
Write Request Examples 1.2:
Function
Command
Response
Turn Channel On
(1on)
turns on amplifier channel 1 on
Select Input
(1sl4)
turn amplifier channel 1 to input 4
Set Volume
(1vl50)
turn amplifier channel 1 to volume 50
(of 87)
