NOVUS fieldlogger - Manual

NOVUS AUTOMATION 1/16
MODBUS COMMUNICATION MANUAL
INTRODUCTION
FieldLogger has many communication interfaces. Among all of them, we can highlight some that can be used as
Modbus slaves:
RS485, acting as a slave in Modbus RTU protocol.
USB device, acting as a slave in Modbus RTU protocol.
Ethernet, acting as a server in Modbus TCP protocol.
All device configurations, as well as the input channels reading, are made through Modbus protocol.
In this manual, all needed information to read FieldLogger ’s input channels data without using the Configurator
application can be found. In order to assure the correct configuration and data download, always use the indicated
software applications. After configuring the equipment, data obtained from its inputs and outputs can be reached by any
other software application that has Modbus RTU or Modbus TCP communication abilities.
Further details about the implementation of a network of Modbus devices over RS485 can be found in the RS485 &
RS422 Basics file, available in the FieldLogger CD or in the
www.novusautomation.com website for download.
MODBUS COMMANDS
The following listed Modbus commands (or functions) are implemented. In order to get more information about each one
and about Modbus protocol in general, check the website:
http://www.modbus.org
READ HOLDING REGISTERS
– 03H
This command can be used to read one or more holding registers, as listed in a table in the next chapter.
WRITE SINGLE COIL – 05H
This command can be used to write in digital output or relay. First coil refers to digital output 1. Ninth and tenth coils refer
to relays 1 and 2.
Important Note: It is not possible to write in a digital channel that was configured as an input. It is also not possible to
write in a digital output or relay that was configured to be controlled by alarms (internal FieldLogger alarms).
WRITE SINGLE REGISTER
– 06H
This command can be used to write in one holding register, as listed in a table in the next chapter.
WRITE MULTIPLE REGISTERS
– 16H
This command can be used to write in a block of holding registers, as listed in a table in the next chapter.
HOLDING REGISTERS TABLE
The specified addresses are related to the low-level phisical addresses, where zero (0) means the PLC address 40001.
Minimum and Maximum columns have the valid range for each parameter. R/W column indicates whether the parameter
is writable (R/W) or read-only (R). SuperView Mnemonic informs what is the register mnemonic in the SuperView
SCADA software.
Address Description Minimum Maximum R/W
SuperView
Mnemonic
0 Serial number (word high) 0 65535 R SerialNumber_H
1 Serial number (word low) 0 65535 R SerialNumber_L
2 Firmware version 0 999 R FirmwareVersion
3 Analog channel 1 value (signed 16-bit integer) -32768 32767 R Analog_1_Int
4 Analog channel 2 value (signed 16-bit integer) -32768 32767 R Analog_2_Int
5 Analog channel 3 value (signed 16-bit integer) -32768 32767 R Analog_3_Int
6 Analog channel 4 value (signed 16-bit integer) -32768 32767 R Analog_4_Int
7 Analog channel 5 value (signed 16-bit integer) -32768 32767 R Analog_5_Int
8 Analog channel 6 value (signed 16-bit integer) -32768 32767 R Analog_6_Int
9 Analog channel 7 value (signed 16-bit integer) -32768 32767 R Analog_7_Int