Notes - Frick QUANTUM ACUair Setup

Now that the Leader knows which panel is responding, 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.
: 01 03 02 00 DC 1E
Where:
Start of Message
Quantum™ ID #
Read Function
Number of Bytes Returned
Data
Error Correction Code
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.
: 01 03 02 00 DC 1E
Where:
Start of Message
Quantum™ ID #
Read Function
Number of Bytes Returned
Data
Error Correction Code
The next two bytes (in this case) are the actual data in
response to our original request.
: 01 03 02 00 DC 1E
Where:
Start of Message
Quantum™ ID #
Read Function
Number of Bytes Returned
Data
Error Correction Code
®
FRICK QUANTUM™ ACUair
COMMUNICATIONS SETUP
®
CONTROL PANEL
We need to know what this value means. To break it
down, we must convert the pair of bytes from Hex to
Decimal:
00DC (hex) = 220 (decimal)
Data to and from the Quantum™ are integer values with
one decimal field assumed unless shown otherwise 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:
220 (decimal) = 22.0 (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:
22.0 (decimal) = 22.0 C
Therefore, the value of the Outside Air Temperature for
°
Unit 1 is 22.0 C.

NOTES:

This has been an example of how the Quantum™
Controller uses the Modbus Protocol. It is hoped that the
information provided here will assist the end user in writing
applications that will allow the Quantum™ to be
implemented into networks that the customer may already
have in use.
This information is subject to change at any time, and is
provided as a reference only. Not all areas of the Modbus
Protocol can be handled in this document. Some
additional information regarding Modbus Protocol that the
end user should be aware of:
•
There are many versions of Modbus Protocol that
is available, and an application that works
properly on one system, may not function
identically on another.
•
Some versions of Modbus Protocol may require
the user to increment any referenced addresses
by "1" (one). For instance, if you wanted to look
®
at Frick Address 135, you may need to actually
look at address 136. The Quantum™ addressing
begins at 0 (zero), whereas some Modbus
Protocols begin at 1 (one), therefore, you may
need to compensate.
•
DO use Modbus ASCII. DO NOT use Modbus
RTU.
•
Use 7 Data bits.
•
Follow the Frick
communications requirements.
S90-500 CS
Page 25
®
specifications for data