Lightspeed CAT 860, User Manual

Page: 30 / 88

30
1. Overview
2. Setup & Use
3. Optional
Accessories
4. T
roubleshooting
5. W
arranty
, Safety
& Specifications
13. RS-232 SERIAL INTERFACE
PROGRAMMING
The CAT 860 uses standard RS-232 protocols as a serial link to an external
control module such as an intelligent wall panel, or a personal computer.
When the Control Select switch in the “RS-232” position, the serial link
offers remote access to operational control circuitry within the CAT 860 for
the purpose of controlling the volume of the audio input and output ports.
Additionally, the serial links allows remote queries of internal CAT 860 system
status.
Command and parameter characters travel serially along the RS-232 signal link
between the external controller and the CAT 860. The command and parameter
information is in the form of two hexadecimal values contained in the 8-data bits
of each RS-232 character. The above graphic illustrates a typical RS-232 logic
waveform representing a character (Data format: 1 Start bit, 8 Data bits, No
Parity, 1 Stop bit). The data transmission starts with a Start bit, followed by the
data bits (LSB sent first and MSB sent last), and ends with a “Stop” bit.
The voltage of Logic “1” (Mark) is between -3VDC to -15VDC, while the Logic “0”
(Space) is b3VDC to +15VDC.
RS-232 Data Signals
RS-232 LOGIC WAVEFORM (8N1)
Serial Interface Protocol
CAT 860 RS-232 SETTINGS
Sync. Method: Asynchronous
Stop Bits: Accepts 1 or 2 stop bits
Baud Rate: 9600 baud
Parity: None
Data Size: 8-bits
Connector: 9-Pin, Female D-Sub