4180ETRS
Operators Manual
24
Serial Operation
The serial communications uses 8 data bits, one stop bit, and no parity. The set-point and other
commands may be sent with the serial interface to set the temperature set-point and view or program
the various parameters. The interface commands are discussed in
Digital Communication Interface
.
Command Syntax
Infrared Calibrators accept commands for setting parameters, executing functions, or responding with
requested data. These commands are in the form of strings of ASCII-encoded characters. The Product
command syntax conforms to SCPI-1994 as closely as possible. One notable exception is that
compound commands are not allowed as explained below.
Commands consist of a command header and, if necessary, parameter data. All commands must be
terminated with either a carriage return (ASCII 0D hex or 13 decimal) or new line character (ASCII 0A
hex or 10 decimal).
Command headers consist of one or more mnemonics separated by colons (:). Mnemonics may use
letter characters, the underscore character (_), and possibly numeric digits as well. Commands are not
case sensitive. Mnemonics often have alternate forms. Most mnemonics have a long form that is more
readable and a short form consisting of three or four characters that is more efficient.
A mnemonic may end with a numeric suffix that specifies one of a set of independent function blocks
such as input channel data paths. If a numeric suffix is omitted when a particular block must be
specified, an error is generated (
Header suffix out of range
).
Query commands are commands that request data in response. Query commands have a question
mark (?) that immediately follow the command header. Responses to query commands are generated
immediately and placed in the output buffer. Responses are then transmitted automatically over the
RS-232 port. Responses are lost if not read before the next command is received.
Some commands require parameter data to specify values for one or more parameters. The command
header is separated from the parameter data by a space (ASCII 20 hex or 32 decimal). Multiple
parameters are separated by a comma (,).
The Product does not allow compound commands (multiple commands per line separated with
semicolons). All commands are sequential. The execution of each command is completed before
subsequent commands are processed.
