YSI IQ SensorNet MIQ/A-MOD Module - Manual (Page 6)

Overview MIQ/(A-)MOD
6 ba76021e01 01/2012
1.2 Modbus and IQ S ENSOR N ET system 2020 XT USB
System communication The functional units of the IQ S ENSOR N ET are connected with one
another via a common line (Fig. 1-2). The line consists of two wires and
a shield. It transports digital information between the controller and the
other modules. At the same time, the line is used to supply all modules
with electrical voltage from a power supply unit. The power supply unit
is only required for power supply and is not used in the system
communication.
With the -MOD option, the MIQ/(A-)MOD module upgrades the system
communication by a Modbus interface. Via this interface, sensor data
can be queried with the Modbus RTU protocol. The Modbus interface
(RS 485) also enables a direct point-to-point connection from an
IQ S
ENSOR N ET system to a Modbus master (e.g. PC or PLC).
Fig. 1-2 Functional units of the IQ S ENSOR N ET with connection to the Modbus
Note
All other general information on components, functions and operation
of the IQ S
ENSOR N ET system 2020 XT USB is given in the system
operating manual.
With the A option, the MIQ/(A-)MOD module extends the
IQ S
ENSOR N ET system by a fully automatic air pressure compensation
for D.O. sensors (see system operating manual).