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 for the application, depending on the amount of data 2 GB for the database, 256 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 when installing the system. Also the base station can notify SensorGraph about possible communication problems if configured.
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 built-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 supporting it. A special trip value message is sent to the base station when a measurement is below the minimum or above the maximum trip value. These trip values can also operate a relay on the base station if present. Alternatively, alarm conditions can be set in the SensorGraph PC program allowing alarms to be sent to a mobile phone, to an email address, shown in a pop-up box on the screen or shown in graphs.
Is it possible to export data into Excel or save as .csv file?
The SensorGraph PC program saves logged data in a database (Apache Derby). An Export function is available to make a readable version that can be inmported 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 0-25mA 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, WS-BU-ethernet 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 WS-BU-ethernet base station is designed for connection to a LAN.
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?
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