20 Serial Communication
Using Gas Select™ and COMPOSER™
To reconfigure your flow meter to flow a dierent gas, look up its gas number (page 24).
For more information on how Gas Select™ and ™ work, see page 13. Here are
the commands:
Choose a gas: [unit ID]g[Gas Number]
Example 1: ag8 (reconfigures to flow nitrogen)
Example 2: ag206 (reconfigures to flow P-10)
User mixes are selected in the same way. All ™ gas mixes have a mix number
between 236 and 255.
Choose a user mix: [unit ID]g[Gas Number]
Example: ag255 (reconfigures for user mix 255)
Defining a new ™ gas mix is faster using serial commands than using the front
panel. The basic formula for this is:
[unit ID]gm [Mix Name] [Mix Number] [Gas1 %] [Gas1 Number] [Gas2 %] [Gas2 Number]...
[Mix Name] Use a maximum of 6 letters (upper and/or lower case), numbers and symbols
(period or hyphen only). This is equivalent to the short name when creating a mix via the
front panel (page 14).
[Mix Number] Choose a number from 236 to 255. If a user mix with that number already
exists, it will be overwritten. Use the number to assign the next available number to your
new gas. Gas numbers are assigned in descending order from 255.
[Gas1 %] [Gas1 Number]... For each gas, enter its molar percentage up to 2 decimal places,
then its gas number (page 24). 2–5 gases are required, and the sum of all gas constituent
percentages must equal 100.00%. After creating a mix, the meter will confirm the new gas:
Example 1: Create a mix of 71.35% helium, 19.25% nitrogen, and 9.4% carbon dioxide as
Gas 252, called “MyGas1”.
Command:
agm MyGas1 252 71.35 7 19.25 8 9.4 4
Response: A 252 71.35% He 19.25% N2 9.40% CO2
Example 2: Create a mix of 93% methane, 3% ethane, 1% propane, 2% nitrogen, and 1%
CO2, using the next available gas number, called “MyGas2”.
Command: agm MyGas2 0 93 2 3 5 1 12 2 8 1 4
Response: A 253 93.00% CH4 3.00% C2H6 1.00% C3H8 2.00% N2 1.00% CO2
To Next Page
Loading...
