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2.4 FX-300-ISE Module Description
2.41 Sensor Input
The sensor without preamplifier is connected directly to the FX300-pH/ORP/ISE module. The mV
signal from the sensor is processed by an integrated high impedance amplifier. The FX300-
pH/ORP-X hardware version can support internal or external preamplifiers to enable installations
that require long cable lengths or to operate in high interference areas. Temperature measurement
with a Pt100/Pt1000 element in the sensor allows automatic temperature compensation to be
performed
.
2.42 Analog Output
The FX300 transmitters have a single scalable analog output of either 0-20 or 4-20 mA (selectable).
The difference required between the minimum (0/4mA) and maximum (20mA) output is 20% of the
selected range (low 0-10, mid 0-100 or high 0-1000 ppm). For example, if the low range (0-10) is
selected then the output could be as narrow as 0-2 ppm for the 0/4-20 mA scaling. The output is
proportional to ISE ppm or temperature and is galvanically insulated from the input.
2.43 Factory Reset
You can use parameter (P20) on the FX-300-ISE transmitter to reset the unit back to the factory
dispatched configuration. If you perform a factory reset you will need to re-scale the current output
and and re-configure alarm settings and limits. You will also need to repeat your 2-point calibration
using calibration solutions that are one decade (lOX) apart in value. In addition, you will need to once
again place the ISE sensor back into service and allow it to reach equilibrium. You will then also need
to repeat your 1-point grab sample offset calibration.
2.44 RS485 Modbus (Optional)
RS485 Modbus output is available in two ways.
1.
It can be integrated into the pH or ISE module at time of order only.
2.
It is also available in the FX-300-TOT module, which can be added at any time.
Acquired data is transferred using Modbus standard for multi-drop communication and is connected
using RS485. The Modbus-master may be the FX300-DAT data logger module or any SCADA
system. When units are ordered with Modbus option, the free of charge Windows data logging and
graphing software and be used to monitor and record all process and temperature values from up
to 247 transmitter simultaneously at distances up to 6500 feet (2 kilometers).
In order to utilize the Modbus interface the FX-300-ISE must be ordered with Modbus. FX-300-ISE
may be used as a slave for the ‘Dat’ - unit FX-300-DAT or as a slave in a SCADA system. The setup /
communication for each case will be explained in the following.
Modbus With FX-300-DAT
If FX-300-ISE is used together with the FX-300-DAT data logger, the user must pay attention to two
things: The baud rate on the Modbus as well as the address of the FX-300-ISE. The baud rate
(P14)
must be set to the baud rate of the FX-300-DAT. Whether a baud rate of 19,200 or 9,600 is
used is of no importance, as long as all units on the Modbus are set to the same baud rate.
2 Introduction
