51
50
The time-out for the first character of the controller answer is
100 milliseconds.
The minim delay between the last received character and first
character of the answer is 15 ms.
When the controller answers to the ECR, TDR and TMR com-
mands, the reading is sent as ASCII string followed by a
character indicating the control and alarm status of the
controller and info for controller setup modified.
This character can assume the following values:
•
“A”
control and alarm are ON;
•
“B”
control and alarm are ON and need update controller setup
(GET commands);
•
“C”
control is ON and alarm is OFF;
•
“D”
control is ON and alarm is OFF and need update control-
ler setup (GET commands);
•
“N”
control and alarm are OFF;
•
“M”
control and alarm are OFF and need update controller
setup (GET commands);
For example, a possible answer to the TMR command is:
“03<STX>10.7C<ETX>”
meaning that the current temperature reading is 10.7°C,
the control action is active and no alarm condition is present
and controller setup is updated on PC.
“015••<CR>”
This command sets the setup item 33 (max. relay ON time) of
a controller, identified by the process ID number 01, to 15
minutes. The
•
character means blank.
Once the controller has received a command, it answers
with its 2-digit process ID number followed by:
•
ACK
(Hex 06)
If the controller recognizes the received command and per-
forms the requested task;
•
STX
(Hex 02),
Data
,
ETX
(Hex 03)
If the received command is a request of data;
•
NAK
(Hex 15)
If the received command is not recognized (e.g. The syntax
is wrong);
•
CAN
(Hex 18)
If the controller cannot answer the request (e.g. the pass-
word was not sent, the controller is in setup mode, the setup
item is not available in that model, etc.)
Note
The controller answers to the GET command with the same
data format explained in the SET command.
Following are examples of answers:
“03<STX>+01200<ETX>”
The controller with process ID number 03 says that its cur-
rent setpoint is +12.00mS.
“01<STX>UE24_21225<ETX>”
The controller with process ID number 01 says that it is a
HI24212 model with firmware release 2.5.
