Reference Manual Rev 1.13
Page 92
004R-646-113
CMD
is a two character hexadecimal field:
CMD
Command
Description
05
H
Read Literal
Read register contents in a ‘human readable’ format
11
H
Read Final
Read register contents in a hexadecimal data format
16
H
Read Final
(Decimal)
Same as Read Final except numbers are decimal.
12
H
Write Final
Write the DATA field to the register.
17
H
Write Final
(Decimal)
Same as Write Final except numbers are decimal.
10
H
Execute
Execute function defined by the register using
parameters supplied in the DATA field.
REG
is a four character hexadecimal field that defines the address of the
Register specified in the message. See Appendix 3: Communications
Registers page 123 for a list of registers used by the instrument. The
viewer software will show the register address for each setting in the
menu structure when they are accessed.
: DATA
carries the information for the message. Some messages require no
DATA (eg Read Commands) so the field is optional. When a DATA
field is used a ‘:’ (COLON) character is used to separate the header
(ADDR CMD REG) and DATA information.
is the message termination (CR LF or “;”).
Note:
The hexadecimal codes are combined in the fields described above when
multiple options are active at the same time. For example an error response
message from instrument address 5 would have an ADDR code of C5
H
(80
H
+ 40
H
+
05
H
).
14.2.2.
Termination
Message termination is possible in two ways.
For normal communications that do not involve checksums use either a
CRLF (ASCII 13, ASCII 10) as a terminator or a semicolon (‘;’ ASCII ). There
is no start-of-message delimiter.
To use a checksum the message is framed as:
SOH
<Message>
CRC
EOT
SOH
ASCII 01
CRC
a 4 character hexadecimal field comprising the 16 bit CRC checksum. The
CRC uses the 16 bit CCITT polynomial calculation and includes only the
contents of the <Message> section of the transmission.
EOT
ASCII 04
