Frick QUANTUM LX Control Panel, Руководство по обслуживанию

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QUANTUM ™ LX EVAPORATOR CONTROL PANEL
COMMUNICATIONS SETUP
090.610-CS (MAY 2016)
Page 36
Byte Count in data returned
Data in register 2000
Data in register 2001
Response 01 Out: 00
.
00 00
.
00 00
.
07 01 03 04 00
.
20 00
.
16
Command 00 In: 00 . 00 00 . 00 00 . 06 01 03 07 . D0 00 . 02
# of registers to read
Address of first register (2000)
Read Holding register
Modbus ID
# of bytes in command
Always 0 for Modbus TCP
Transaction Identifier
• The function code field of the message
frame will contain 8 binary bits
• Word size is selectable.
• Error checking is accomplished using
CRC (Cyclical Redundancy Check).
• Hyperterminal cannot be used to test
communications.
Serial Port Configuration Of The Master
7 or 8 Bits per Character (Data Bits)
Odd, Even or No Parity
1 or 2 Stop Bits
No Handshake
Data Packet
The MODBUS® protocol establishes the format
for the Master’s query by creating a message
(data packet) as follows:
• Assign the device address (Quantum™
panel ID #). The address field of a mes-
sage frame contains two characters for
ASCII, or 8 bits for RTU. Valid Quan-
tum™ device addresses are in the range
of 01 – 99 decimal. A master addresses
a Quantum™ by placing the Quantum™
address in the address field of the mes-
sage. When the Quantum™ sends its
response, it places its own address in
this address field of the response to let
MODBUS® ASCII (Serial Communications)
In the ASCII Transmission Mode (American Stan-
dard Code for Information Interchange), each
character byte in a message is sent as 2 ASCII
characters. This mode allows time intervals
of up to a second between characters during
transmission without generating errors. Some
particulars about MODBUS® ASCII:
• The device address field of the mes-
sage frame contains two characters (16
bits).
• The function code field of the message
frame will contain two characters (16
bits).
• Word size is selectable.
• Error checking is accomplished using
LRC (Longitudinal Redundancy Check).
MODBUS® RTU (Serial Communications)
In RTU (Remote Terminal Unit) Mode, each 8-bit
message byte contains two 4-bit hexadecimal
characters, and the message is transmitted in a
continuous stream. The greater effective char-
acter density increases throughput over ASCII
mode at the same baud rate. Some particulars
about MODBUS® RTU:
• The device address field of the mes-
sage frame contains 8 binary bits.
The top line of data is the most recent activity.
At the left of each line, you should see whether
the data is IN or OUT (Response or Command),
and the actual data (in Hexadecimal format). This
information can be used to compare against the
data being sent and received at the other end of
the communications link, to verify proper opera-
tion.
Refer to the following table for an example of
how the data packets are created, using the data
that has been shown on the above screen.
The following user selectable button is provided:
• [Refresh]
This screen allows the technician to view the
ModBus TCP data communications information
that the Quantum™ LX is receiving and trans-
mitting.
Each time a new command is sent or received,
the screen will need to be refreshed by selecting
the
[Refresh] button.