3 Installation | Model 3020T |
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•The range in use (HI, MED, LO)
•The span of the range (0-100 ppm, etc)
•Which alarms—if any—are disabled (AL–x DISABLED)
•Which alarms—if any—are tripped (AL–x ON).
Each status output is followed by a carriage return and line feed.
Three input functions using RS-232 have been implemented to date. They are described in Table 3-4.
| Table 3-4: Commands via RS-232 Input |
Command | Description |
as<enter> | Immediately starts an autospan. |
az<enter> | Immediately starts an autozero. |
st<enter> | Toggling input. Stops/Starts any status message output from |
| the RS-232, until st<enter> is sent again. |
The RS-232 protocol allows some flexibility in its implementation. Table 3-5 lists certain RS-232 values that are required by the 3020T imple- mentation.
Table 3-5: Required RS-232 Options
Parameter | Setting |
Baud | 2400 |
Byte | 8 bits |
Parity | none |
Stop Bits | 1 |
Message Interval | 2 seconds |
3.3.9 Remote Sensor and Solenoid Valves
The 3020T is a single-chassis instrument, which has its own sensor and, in the –C option, its own gas-control solenoid valves. The REMOTE SEN- SOR connector is not used, and the SOLENOID RETURN connectors are used (without the –C option) to synchronize external gas control valves, if desired. See Figure 3-7.
3-10 | Teledyne Analytical Instruments |