Graseby 3000/500, Manual

Page: 213 / 231

Graseby Medical L t d Volumetric Infusion Pumps
3000/3100 and 500/505 Service Manual Issue 1(April 2002) 12 - 15
Record Terminator
The last character of any record transmitted by the host or pump will
be an ASCII ">" (3E hex). The use of this character is not allowed in the
command parameter area.
Additional non-message characters are allowed following the record,
such as a line feed or carriage return. These are not required and the
pump ignores such characters.
Return Record Format
A return record consists of a string of characters sent from the pump
to the host as a result of a command record sent to the pump. The
general format can be summarized as follows:
< LLRAAAAAADDDXXXX >
where:
< = record header 1 character
LL = record length 2 characters
R = return code 1 character
AAAAAA = alarm bytes 6 characters
DDD = command data variable length - 0 to 17
characters
XXXX = record CRC 4 characters
> = record terminator 1 character
Total - 15 to 32 characters
The record header, record length, CRC field, and record terminator
are as described above for the command record, with the following
exceptions/additions:
• The valid values in the length field can be from 15 to 32 bytes.
•
The command parameters are replaced with the alarms bytes and
the variable length command data.
• The command code is replaced with a return code.
The return code field of the return record can be any of the following:
0 - Command Accepted No problems were detected with command or its
execution
1 - Invalid Length Field Length field does not match actual message length
2 - Message too short Message does not meet minimum length
requirements
3 - Message too long Message exceeds maximum allowed length
4 - Invalid CRC Field CRC field does not match calculated message CRC
5 - Invalid Command Code The command code is not for one of the supported
commands
6 - Invalid Parameter Parameter is out of range or missing - See Table 1
7 - Invalid Mode See Table I for modes when commands are not valid
The host should always check this return code and verify that it is
'Command Accepted'. In addition the host should verify through the
use of other information returned from the pump, that a command was
carried out properly. (e.g. after executing the 'change rate' command,