Operating instructions

Protocol answer Communication protocol
8 KNF Flodos CP_SIMDOS02_EN_01_166851
7 Protocol answer
First, the pump checks the formal correctness of any received
command. The Format as described in this document and LRC
have to be correct. The address in the received packet has to be
equal to the pump’s address. After the acceptance of the com-
mand, it will be executed.
If the command has been executed, the processing of the com-
mand is either positively or negatively acknowledged.
Positive acknowledge ACK (deciaml 6) means a successful pro-
cessing of the command.
Negative acknowledge NACK (decimal 21) means either a formal
error while receiving the command or a failure to process the
command. No details are available.
If the command to the pump demands a reply (i.e. status infor-
mation or the value of a parameter), a leading ACK indicates the
successful processing of the command. Afterwards the actual
content of the answer is transmitted. In case of an invalid com-
mand a single NACK is returned.
Example: An answer for a formally correct command that demand-
ed a reply, like: ?SI (Pump Address)
Name STX Address Cmd str ETX LRC
Example 2 0 0 ? S I 3 36
Meaning Ack STX Data ETX LRC
Example #6 2 0 0 3 1
The Pump address is 00.
#6 ACK
STX (02h) Start of text
Data block ASCII code according to the command list
ETX (03h) End of text
LRC Checksum
Overview of protocol response of the pump
Situation of received packet
Response
Remarks
Correct LRC, Address match,
formally correct content and
command successfully executed
ACK Formally correct means a valid command mne-
monic and the right number of digits for the
parameter
Formally incorrect content NACK Invalid mnemonic or parameter field contains an
incorrect number of digits
Parameter out of range NACK Any set parameter is range checked
Command not executed NACK An internal state prevents the command from
execution
Wrong LRC No answer ‘U’ is generally accepted as a valid LRC for any
received packet
Wrong address No answer
Address = 99 No answer
:
Transmit
Receive