ELM624
Control L (LANC) to RS232 Interpreter
Description
The Control L or LANC interface is an industry
standard introduced by the Sony Corporation for
controlling audio and video devices. It uses a bit
serial data format, and requires that the controller be
synchronized to the controlled device – something
which is difficult to do using standard serial
interfaces. The ELM624 is an 8 pin integrated circuit
that performs the synchronizing function for you.
All user interaction with the ELM624 is by
standard ASCII characters over an RS232 interface.
There is no special formatting required, other than
perhaps an understanding of the hexadecimal
numbering system, nor is there a need for a powerful
PC - virtually any model with a serial port will do.
Since the ELM624 was designed to provide a
cost-effective way for people to experiment with the
Control L system, many features typically found in
commercial devices, such as RS232 handshaking,
variable baud rates, extra buffering of signals, etc.
have not been implemented. Responses are kept to
a minimum as well (eg. a single question mark is
returned for a misunderstood command), but the
general principles of operation are demonstrated
and for many applications, this is all that is required.
Features
• Low power CMOS design
• Enable input allows control of multiple devices
• Configurable with simple AT commands
• ASCII output formatted as standard hex digits
• Oscilloscope trigger pulse output
• Power control pulse output
• Crystal controlled for timing accuracy
• Works with 50 Hz and 60 Hz systems
• Power up to monitor mode
Connection Diagram
PDIP and SOIC
(top view)
V
DD
XT1
XT2
1
2
3
4
8
7
6
5
V
SS
LANC
Tx
Rx
Applications
• Video editors
• Time-lapse recording controllers
• Programmed control of A/V equipment
• Remote camera controls
Enable
3.58MHz
Block Diagram
XT1
V
DD
Enable
4
2
3
XT2
Control
V
DD
Rx
Tx
5
6
RS232
Interface
Control L
Interface
V
SS
7
LANC
ELM624DSD
Elm Electronics – Circuits for the Hobbyist
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