VBOX 3i User Guide
Page 18 of 46
28/08/2013
Analogue inputs (A In)
The VBOX 3I contains four differential 24bit analogue input channels with a maximum sample rate of 100Hz. Each channel has its own dedicated analogue to digital
(A/D) converter with all four channels being sampled synchronously to each other. The voltage range of the input channels is ±50volts. Note that unlike the ADC03
module, the analogue channels in the VBOX 3I are not electrically isolated from each other.
The analogue input connector also contains voltage outputs that can be used to power external sensors. These are a Vbatt connection which is equal to the VBOX
input voltage level and a DC isolated 5 V Out connection which is equal to 5V ±2%. Both Vbatt and 5V Out connections are internally protected by 100mA thermal
fuses. For connector pin configuration see page 16. A screw-terminal connector block is available as an option for easy connection of signal pins.
Using the VBOXTools software, logging of the analogue channel data can be switched on or off. It is also possible to change the name of each input channel and
configure scale and offset values for calibration of sensors. A scale value of 1 and offset of 0 correspond to a channel reading in Volts DC. This means that the value
stored on the compact flash card for the channel will also be in volts. When using a sensor such as a load cell, it may be desirable to store a reading in Kg. In this
case, changing the scale and offset to suit the sensor data sheet allows the data stored onto the compact flash to be in Kg. When changing settings for an analogue
channel using the VBOX.EXE software, a live data view of the current channel is shown. The value shown is the value after scale and offset is applied and can
therefore be used to aid sensor calibration.
NOTE: The 5V regulated output on pin16 is only good for VBOX power supply voltages >8.5V
Note: A 25W D-sub to 4W BNC adaptor
block is available through your VBOX
distributor, part number RLVBACS054
