Pressure Systems 9816 Scanner User Manual


 
Pressure Systems, Inc. 98RK-1 & 9816 User’s Manual©
Page 107 www.PressureSystems.com
result should always be restored into the transducer’s non-volatile memory afterwards. In some
cases, the user’s application may not require such a comprehensive adjustment as the other
factory-determined pressure/temperature coefficients (stored permanently inside each
transducer) are extremely stable. Only an occasional Re-zero adjustment may be all that is
necessary.
When instructed to execute a particular sequence of sub-commands of the Configure Multi-
Point Calibration ('C') command, the module will perform the various stages of the Multi-Point
Calibration adjustment calibration function, and then update both the offset and gain coefficients
in the module’s volatile (e.g., RAM) memory. The module will use this newly calculated data
term for all subsequent engineering-unit calculations.
Note
When using the Configure/Control Multi-Point Calibration ('C')
coefficients in transducer non-volatile memory.
4.4.1. Calibration Valve Control
Before executing a Multi-Point Calibration adjustment (using various forms of the
Configure/Control Multi-Point Calibration (‘C’) command), Model 9816 modules should have
their calibration valve placed in the proper position. For modules with only one common
pressure range for its transducers, the CAL position should be used since the span calibration
pressure can be applied between the CAL 1-8 and CAL REF ports (see Section 4.3.1 for more
information on these ports). Since the module will not attempt to shift this valve automatically,
as it does for Re-zero adjustment, it should be placed in the desired position manually with the
Set Operating Options ('w') command (option indexes = 0C and 12). This is illustrated in the
example of the next section.
When multi-point calibrating Model 9816 modules with multiple ranges installed, the CAL port
may be used to apply pressure to all transducers only if the specified proof pressure is not
exceeded on any channel. If the application of a specific span pressure exceeds the proof
pressure rating of any other transducer contained within the same scanner, the calibration
pressures must be applied to the RUN side pneumatic input ports. Since the calibration
command ('C') has a channel selection bit map parameter allowing it to calibrate only the
desired pressure channels, the RUN port is a viable option for supplying the calibration
pressures.