Teledyne D series Installation And Operation Manual page 173

The system is now running and the network controller continues
the polling scheme. If the controller gives an improper command,
the units will respond with a problem message indicating the
type of error.
The format of the message is given in section 8.8 of this manual
and specifies the commands used for this instrument. It is
important to follow this format. Spaces are ignored anywhere
within the message field. Commands must be in uppercase
letters. The network definition allows multiple commands in a
message field when delimited by semicolons, but the D Series
controller is limited to single commands. It will respond with a
PROBLEM=INVALID COMMAND message.
D Series Syringe Pumps
Section 8 Serial Interface
8-19