20
Control
automatically when the setpoint had been set to 0 for at least two seconds.
To disable autotare
(controllers only): write 0 to register 515.
Flow Averaging
Flow averaging governs how the flow sensor reports data, an integer 0–2500 ms. A higher
flow averaging setting will smooth the data, which can be useful for rapidly fluctuating flow
readings.
The time constant is approximately [value] milliseconds.
To read the current averaging
: read register 55.
To change the averaging value
: write an integer from 0–2500 to register 55.
Totalizer
The totalizer measures the total flow that has passed through the instrument since it was
powered on or since it was last reset. Totalizer counts are reset if power is lost.
To read the totalizer
: read registers 2104–2105. The value will be in the volume units of
the instrument, scaled by the factory-set number of decimal places.
To reset the totalizer
: write 0xAA55 (43605) to register 53.
Batch Dispensing
Batch dispensing (controllers only) flows a set volume of gas, after which the valve closes
and flow stops. You can repeat batches.
To read the volume remaining for the current batch
: read registers 2108–2109. The
value will be an integer in the current totalizer volume units, with the same scaling as the
total volume (registers 2104–2105).
To set the desired volume for the totalizer batch
: write the value to registers 521–522.
The value must be an integer in the instrument’s current total volume units and scale.
To reset the batch
: write 0xAA55 (43605) to register 53.
Changing the Gas
BASIS 2 instruments are calibrated to measure any of 9 gases:
Gas Number
Short Name
Long Name
0
Air
Air (Clean Dry)
1
Ar
Argon
2
CO
2
Carbon Dioxide
3
N
2
Nitrogen
4
O
2
Oxygen
5
N
2
O
Nitrous Oxide
6
H
2
Hydrogen
7
He
Helium
8
CH
4
Methane
To select a gas
: write one of the gas numbers above, as an integer, to register 2100.
Switch Command Protocol
The unit can be switched from BASIS Protocol 2 (described in this manual) to Protocol 1
(described in the BASIS 1 manual).
To read the command protocol
: read register 56.
