SCHOTT LLS 3 - Remote Operation via RS-232

User Manual - LLS 3
Page 29
13.0 Remote Operation: RS-232
The LLS 3 LED Light Source can be operated remotely via a built-in RS-232 interface.
Power must be applied to the unit to use this interface but the light source does not
need to be turned on. Connect the RS-232 DTE equipment to the light source (DCE)
using a 9 pin straight-through cable. An example Windows Dialog based application
that shows typical RS-232 communication is available on the website and by request.
The terminal emulation settings for communications are as follows:
• 9600 Baud rate
• 8 Bits
• No Parity
• No Handshaking
All commands are acknowledged by a <Carriage return> character or a response from
the command terminated by <CR>.
Command Protocol
Any device that can transmit and receive ASCII characters through RS232 can remotely
control the LED Light Source. The format for most command strings are: &yxx<CR>, where
& = header character
y = command character
xx = one or two character command parameter
<CR> = carriage return character “/r”
When sending commands, there are certain characters that must be sent in order for a
command to function. Single digit values must be preceded by zeros if the parameter field
requires multiple characters. For example, setting the lamp intensity to zero is: &i00.
Commands are not case sensitive. The LLS 3 buffers ASCII characters until a carriage return
is received. The buffer is automatically cleared after a command is processed. Invalid
commands are also cleared by receiving a carriage return or after a 10 second command
timeout.
Negative Acknowledgements
Negative acknowledgements are used to indicate that a received command was invalid. The
following negative acknowledgements are supported.
i.
Invalid Command: Not a recognized command: &ncx
1. c = constant character denoting command not recognized
2. x = command character received
ii. Invalid Parameter: A command parameters is invalid: &nypxx
1. y = command character
2. p = constant character denoting invalid parameter error
3. xx = received data
4.
iii. Value Out of Range: Value of the command parameter exceeds the command‘s range: &nyrxx
1. y = command character
2. r = constant character denoting out of range
3. xx = received data