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Operation of the instrument
4.1 Connecting up the Q-Daq.
The Q-Daq has one connector and cable which supplies the unit with power and also provides CAN
(Q-Daq DC only) and Ethernet comms. Ensure all the connections are made before powering up the
Q-Daq.
The Q-Daq should not be hot plugged with the power connector. Doing so can cause
permanent damage to the unit. Always switch the power at the power supply source.
Upon power up, the blue LED will light constantly while the Q-Daq boots up. This will typically take
around 2 seconds. When the Q-Daq has finished booting, the blue LED will flash at a constant rate to
show that the system is running (unless auto hardware trigger enable has been set – see later).
To connect to the Q-Daq, establish an Ethernet connection to the Q-Daq using the appropriate cables
and check that the necessary link lights are lit. The host PC must have an i/p address in the same
range as the Q-Daq. For example, if the Q-Daq had an i/p address of 192.168.1.190 then (depending
on the subnet mask used) the first three octets of the subnet mask should be the same – i.e.
192.168.1.XXX. Once the connection has been established, the i/p address can be changed and the
Q-Daq connected to the user network.
NOTE: If the i/p address is changed, it is very important that a record is made of the new i/p address
as it cannot be ascertained without returning the unit to Chell Instruments.
4.2 Configuring the Q-Daq
The Q-Daq is designed to be configured by using the embedded web server. Here all the product
variables may be changed including i/p address, CAN i/d, averaging, transmission speed etc. Once
these setting are configured, they can be permanently saved by clicking on ‘BURN TO EEPROM’.
Once the unit is reset, the Q-Daq will run using these setting.
The Q-Daq can be configured to output data over CAN (Q-Daq DC only) or Ethernet (TCP/IP or UDP)
and, if configured to do so, it will output this data immediately upon power up. The Q-Daq can also
accept commands over the Ethernet or CAN networks to configure the majority of the internal setting
(with the exception of CAN i/d, i/p address and some lower level functions). Please refer to document
900222 – nanoDaq-LT user programming guide for available CAN and Ethernet commands and the
format of the data output stream.
4.3 Re-zeroing the Q-Daq.
It is possible to re-zero the output of the Q-Daq for either absolute or differential measurements.
The Q-Daq is re-zeroed by sending the appropriate command over the CAN or Ethernet link via the
Chell software or via the embedded webserver. The system will then average a number of zero
readings and perform a re-zero. Naturally, there should be no pressure applied to the ports of the
scanner when a re-zero is being performed.
When a re-zero is being performed, the red LED will light momentarily. The re-zero value is not stored
in volatile memory and will be lost upon reset. See section 5.5.4 for permanently saving the zero
values if necessary.
