What are the minimum requirements to get a wireless data logging system (including PC requirements) up and running?
You need at least 1 base station, 1 sensor and a PC for installing the
system. The PC needs to be a Pentium III-650MHz running Windows XP, at least 250
MB of free space on the hard drive, 128 MB of RAM, a CD ROM drive and a RS232
communication port.
What needs to be done when adding more sensors after installation?
A new sensor causes the base station to signal the PC about this event. The PC
opens a window where configuration data of the sensor can be added (friendly
name, minimum and maximum trip values). The base station sends this data to the
sensor and the sensor is ready for operation.
What is the reliability of the radio link between sensor and base station?
Every effort is done to ensure that measurements taken by the sensor
are delivered to the base station and any logging application connected to the
base station. Low level retransmission based on radio interference levels and
application level retransmission based on sequence numbering ensure that
customers can rely on the monitoring function of the system.
What is the maximum distance between PC and base station?
This is determined by the interface type used. For RS232 this is approximately 2
meters. For RS485 this is up to 100 meters.
How can I see if the sensor has connection with the base?
By using the real-time graphing software on the connected PC, the sensor values
can be viewed. It is good practice to have short transmission interval settings
hen installing the system.
Are the sensors working in cold and wet environments?
Yes, sensors operate from -20°C and have an IP65 enclosure, meaning that they
are dust tight and can withstand splashed water and water jets.
Can I place the wireless sensor in a refrigerator?
Yes, this is possible. Please take into account that the possible distance
between sensor and base station is shortened when doing this, caused by the
metal used in the refrigerator housing.
How easy is it to swap the battery?
As easy as opening the cover by removing 4 screws, remove the old battery, place
the new battery and close the lid again with the 4 screws
What happens if the PC does not have power or when communication is not possible between sensor and base station?
If the PC is powered down, the base station can store measurement values in
optional non-volatile memory. When communication between sensor and base station
is not possible, the sensor stores the measurement values in non-volatile memory.
Is the sensor calibrated and according to which standards?
WS-DLTa sensors are calibrated for use with either Pt100 or Pt1000 external
probes. Calibration is done according to IEC751-2.
Is a calibration certificate available?
A calibration certificate can be made available upon request. A fee for
providing the certificate will be charged to the customer.
Can I set alarm trigger points and how does notification take place?
Minimum and maximum trip values can be set in each sensor. A special trip value
message is sent to the base station when a measurement is below the minimum or
above the maximum trip value. Alternatively, alarm conditions can be set in the
SensorGraph PC program allowing alarms to be sent to a mobile phone, to an email
address or shown as a pop-up box on the screen of the PC.
Is it possible to export data into Excel or save as .csv file?
The SensorGraph PC program saves logged data in .csv files. The format used is
for internal use only. An Export function is available to make a more easily
readable version that can be imported in e.g. Excel for creating own graphs. A
document describing this can be found in the Information webpage.
Which external probes can be used and what is the connection?
WS-DLTa sensors can be connected with 2-wire and 3-wire Pt100 and Pt1000 probes
with cable diameter of 3-6mm. WS-DLXa can be connected to any commercially
available sensor with 4-20mA output. WS-DLXv can be connected to any
commercially available sensor with 0-30V DC output.
What can I do with the output connector?
The output connector on the WS-BU-rs485, WS-BU-ana and WS-BU-alm is
controlled by a switched relay. The relay is activated when any sensor measures
a value outside of the preset trip value boundaries. The relay is active for 1
second per alarm notification.
Can the products be repaired?
Faulty products can be sent back to Wireless Value within the warranty period.
They will be repaired or replaced. After the warranty period, a fee for
repairing or cost for new units will be charged to the customer.
Are there particular issues with using the wireless sensors in metal hall environments?
In principle, radio signals do not propagate outside metal enclosures. When
using a mobile phone, this is known as the elevator principle. Inside large
metal halls, radio signals bounce off the walls and cause disturbance for
themselves. The performance of a wireless system inside a metal hall may be less
than specified.
Can I connect the base to my LAN network?
The base station is not designed for connection to a LAN. It may be connected to
a LAN network by using a RS232-to-TCP/IP converter. See the Information
section for a descriptive document.
What other types of connections can be made with the base?
WiSensys base station WS-BU-rs485 has the possibility to connect and integrate
to all kinds of systems with the RS485 connection using the MODBUS interface.
See the Information section for a descriptive document.
What is the maximum RF output power?
The maximum RF output power is 3mW for the sensor and 30mW for the base station.
Why we chose for RF frequency of 868 MHz?
Read more on the 868MHz frequency >>