Antx Messenger 600, User Manual

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4.2 Channel Data
All values read from a Modbus slave device are continually updated and tested as
defined by the configuration parameters. For each channel, based on its type (analog or
digital), there is a basic set of data collected. For purposes of discussion, the term “not
normal” is used to indicate an analog value that has violated a limit threshold or a
digital value that does not match its configured ‘normal’ state.
NOTE: The RemoteIQ configuration should be made to match the configuration in the
Messenger hardware. Alarm notification is only configured in the RemoteIQ system.
5 Modbus
The Messenger can be configured as a Modbus Master, Modbus Slave or both. This is
done by setting the Mode of one of the available serial ports, 2 or 3. Port 2 supports
RS232 and RS485, Port 3 only supports RS232.
5.1 RTU Slave
Being configured as a Modbus RTU Slave device allows SCADA/HMI software to read
channel values from the Messenger. Setting up a serial port is the only configuration
necessary to enable Modbus Slave operation.
The Modbus register map for all channel data values is available on request. Reference
document number “Messenger MODBUS Slave xxxxx”.
5.2 RTU Master
When configured as a Modbus RTU Master device, the Messenger reads register values
from Modbus Slave devices.
In addition to setting up a Modbus Master serial port, channels in the Messenger must
be configured to receive the register values read from the slave device. In Channel
Configuration , define the Modbus Slave address, the register data type to read, the
register number, how to interpret or scale the data being read, and any alarm limits.