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QUANTUM™ LX COMPRESSOR CONTROL PANEL
COMMUNICATIONS SETUP
090.020-CS (JUNE 11)
Page 26
QUANTUM™ $ PROTOCOL SPECIFICATIONS
Quantum™ ($) protocol commands are used by both
the Quantum™ and the Quantum™ LX. This proto-
col has been modi fi ed slightly for the LX, in that the
D command has been eliminated, and the address-
ing structure has changed. Any previously con fi gured
Quantum™ LX protocol applications that had been
written for Quantum™ panels, will still work for the
LX, by using the Map File on the Communications
Screen.
Unless otherwise shown, 9 characters are returned
from the Quantum™ for a data value. The data value
includes two decimal fi elds and the fi rst character
position is either; - if the value is negative, or it is
+ if the value is positive. For example, if the data’s
value is 25.5; then the value +00002550 is sent. All
temperatures are in degree C and all pressures are
in PSIA. A mode such as Slide Valve mode is re-
turned as an integer value that represents the mode
that it is in. For example, a +00000000 is sent if it
is in manual, or a +00000100 is sent if it is in au-
tomatic, or a +00000200 is sent if it is in remote.
The value zero +00000000 is used to represent an
OFF status and a DISABLED option. The value one
+00000100, which is received as a 1, is used to rep-
resent an ON status and an ENABLED option. Set-
points are only changed if the value sent is within the
acceptable range. Reference the Frick® Quantum™
Control Panel Maintenance publication S90.020-M for
the setpoints default settings and ranges. The check-
sum is the 2 byte hexadecimal sum of each character
within the command or returned answer excluding
the command type identi fi er, $. If the command’s
checksum is replaced with ??, the Quantum™ returns
a response without using checksum error checking
on the received command (refer to the Data Packet
section for more information). If the Quantum™ de-
tects a checksum error, a N (Not Acknowledged), the
Compressor ID code, 02, Carriage return, and Line-
feed are returned.
This document will demonstrate how to communi-
cate to the Quantum™ panel using the tables that
appear on the following pages.
Data Packet
If you were interested in viewing the information that
is contained in any of the accessible Quantum™ ad-
dresses, you would want to refer to the table entitled
RETURN DATA VALUE FROM TABLE $IDT1 table later
in this section.
The quickest way to demonstrate this protocol is
through Hyperterminal (see the section entitled Hy-
perterminal later in this manual). After setting up Hy-
perterminal and ensuring that all wiring and jumper
con fi gurations are correct, type a $ symbol. This is
the character that will alert all of the Quantum™
panels on the communications line that data is on its
way. Following the $ symbol, type the ID code of the
Quantum™ that you wish to query (for instance 01 for
the fi rst Quantum™). After the ID number, type a T1.
The protocol code in the Quantum™ recognizes this
portion of the data packet as a request for the data
from a memory location (address).
Up to now you have typed the following information:
$01T1. Now you to need specify the address(s) that
you wish to query. Up to sixteen addresses may si-
multaneously be requested. The format for this entry
must be in the form of four digits, so if you want
to query the Frick address for Suction Pressure (ad-
dress 2002), simply enter the value 2002. Your com-
mand line should now look like this: $01T12002. If
you would like to view additional addresses, simply
continue to append the address numbers to this com-
mand (up to sixteen total). For this example, we will
only use the one address (2002 for Suction Pressure).
The next thing that must be done is to enter a check-
sum value. You may elect to type in a ?? as a wild-
card if you do not have the time to fi gure the correct
checksum, however, the information that is returned
may or may not always be reliable. The checksum will
ensure reliability.
To arrive at the checksum value for the command you
have just typed, you will need to convert each ASCII
digit into hexadecimal (do not include the $ symbol).
For this example, you will need to take the fi rst digit
0, and referring to the Conversion Chart at the end
of this section, look down the ASCII column until you
fi nd 0. You will notice that the Hexadecimal equiv-
alent for ASCII 0 is 30 hex. Repeat the process of
looking up each digit in the ASCII column, and fi nding
its equivalent in the Hexadecimal column, and write
each value down. When all eight (minimum) digits
(01T12002) have been converted to hexadecimal, you
will need to add the eight values together. Remem-
ber, the values are in hexadecimal format, not deci-
mal. If you are not familiar with hexadecimal math,
you may wish to utilize the calculator that comes with
Microsoft Windows. Look at the following chart:
ASCII Value of Data
Packet
Hexadecimal
Equivalent
0 30
1 31
T 54
1 31
2 32
0 30
0 30
2 32
Hex Total = 1AA
The answer that is arrived at from the previous chart
is 1A8.
NOTE: For any calculation that results in an an-
swer of more than two digits, use only the right
most two digits, and disregard all digits to the
left.