Johnson Controls FRICK QUANTUM HD - ASCII Response Example

QUANTUM™ HD COMPRESSOR CONTROL PANEL
COMMUNICATIONS SETUP
090.040-CS (JAN 14)
Page 51
ASCII Response Example
If the packet was properly received by the Quan-
tum™, you should see an immediate response in Hy-
perTerminal. In the Query Response (read function)
example used earlier, a response of :01030205D025
(hex) was received.
Where:
Message Start:
Quantum™ ID #:
Read Function:
# of Bytes Returned:
Data:
Error Correction Code:
: 01 03 02 05 D0 25
}
}
Once again, the first part of the message will be a
Colon (:). This represents a heads up alert that data
is coming down the line, but since the data is com-
ing from the Quantum™ to the Leader this time, the
Leader will accept it.
After having received the Colon (:), the Leader will
look at the two bytes that follows it, so that it may
determine from which Quantum™ the message is
coming from.
Now that the Leader knows which panel is respond-
ing, it needs to known which function the panel is
responding to. In this case, it sees that it is a read
function, and the Quantum™ is merely returning a
value that was previously requested.
Where:
Message Start:
Quantum™ ID #:
Read Function:
# of Bytes Returned:
Data:
Error Correction Code:
}
: 01 03 02 05 D0 25
}
The next byte tells the Leader how many bytes of
information are being returned as a response. In this
case, there are two (2) bytes of valid data.
Where:
Message Start:
Quantum™ ID #:
Read Function:
# of Bytes Returned:
Data:
Error Correction Code:
}
: 01 03 02 05 D0 25
}
: 01 03 02 05 D0 25
}
Where:
Message Start:
Quantum™ ID #:
Read Function:
# of Bytes Returned:
Data:
Error Correction Code:
}
The next two bytes (in this case) are the actual data
in response to our original request.
We need to know what this value means. To break
it down, we must convert the pair of bytes from Hex
to Decimal:
05DO (hex) = 1488 (decimal)
Data to and from the Quantum™ are integer values
with one decimal field assumed unless shown other-
wise or the command is sent to select two decimal
fields.
From the previous paragraph, we can assume that
there is one decimal place to be applied to the data
value that was returned. Therefore:
1488 (decimal) = 148.8 (decimal)
All temperatures are in degrees C and all pressures
are in PSIA unless the command is sent to select the
units of the panel. Therefore:
148.8 (decimal) = 148.8 PSIA
RTU Query (Read) Example
NOTE: Hyperterminal cannot be used to test RTU.
In the following example, a MODBUS® command is
sent to obtain the Discharge Pressure of a compres-
sor. Refer to the following example to see what this
message packet would look like:
: 01 03 02 05 D0 25
}
Where:
Message Start:
Quantum™ ID #:
Read Function:
# of Bytes Returned:
Data:
Error Correction Code:
}