Watts HF scientific 28030, Owner'S Manual

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CLX-XT (28652) Page 15
REV 5 (5/2020)
At any time the standby status can be checked by either Modbus Coil Address 00005 or
Input Address 10005. False (0) indicates standby True (1) indicates measurement cycle
active. Control is only possible through Modbus Coil Address 00005.
5.3 Routine Measurement (Remote Standby Control Option Cat # 25264)
The CLX-XT can operate using Remote Standby Control. Using this optional hardware
control the system will provide one cycle and provide one updated reading each time it is
prompted. It will then go into standby mode and await another prompt. The prompt is a
24VDC signal applied to two contacts.
First, ensure that all plumbing and electrical connections are complete before continuing.
The following steps describe how to measure the value of chlorine of a sample using this
instrument:
1.
Apply power to the instrument. The instrument will perform a water calibration
(WCAL). During this time the RSO contact will be closed, indicating the system is
busy. This automatic calibration is necessary and will only be performed once on
power up.
2. When the system has completed the WCAL, the RSO contacts will open indicating
that it is in standby mode and is ready to take a measurement.
3. Application of 24VDC to the RSI connections will initiate a read cycle. The
RSO contact will close to indicate the system is busy.
4.
At the completion of the cycle, the RSO contacts will open & the measured chlorine
level of the sample will be displayed on the LCD screen. In addition, the equivalent
signal is provided on the analog (4-20 mA) output, or the digital (RS-485) output,
depending on the options selected.
5. The system is now ready to take a new measurement.
Continuous application of 24VDC to the RSI will result in continuously updated
readings.
The instrument needs to take one reading first before proper operation. After the first
reading the operation will continue as below:

Whenever the instrument is in standby the reading will be 0.00 this means the
associated 4-20mA signal will be representative of this reading. If the alarm is set
to LO or HI it will respond to this 0.00 reading.

Whenever the instrument is taking a reading the 4-20mA output and alarm
response will be representative of the reading on the LCD screen.

New readings will be updated as long as 24VDC is applied to the RSI connections.