Setra System Model 470 - Manual (Page 15)

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9. If the response “NO CAL” is received, the program enable switch specified in Step 5 is
not set to “ON”. Transmit C, for CLEAR, and restart this procedure from the beginning.
10. If the 470 responds “UNABLE”, the user defined units have been disabled by use of the
DISABLE UNITS function (Section 5.3). Transmit C, for CLEAR, re-enable the user defined
units (Section 5.3) and restart this procedure from the beginning.
11. Transmit 5 alphanumeric characters, in any combination, to represent the engineering
units of the conversion.
For example, if the transducer is currently reporting in PSI and the desired units are grams
per square centimeter, the ratio is 70.307 g/cm2 per psi (a multiplier). Transmit:
70.307Ug/cm2
The Setra 470 unit will report in g/cm2 to an interrogation.
12. The 470 responds “PROTEC”. Set the program enable switch to “OFF”. Transmit C, for
CLEAR, to resume operation.
4.4 User Defined Engineering Units in Volatile Memory
As in the previous section, you can enter a conversion factor to convert any of the built-in units to
any other pressure units. This function changes the factor in volatile memory only. On power-up,
the factor defaults to that stored in nonvolatile memory by the USER DEFINED UNITS function
(Section 4.3).
Engineering units can be directly changed by entering a multiplier (number to multiply by) or a
divisor (number to divide by), and a series of characters to indicate the name of the engineering
units.)
The conversion ratio is saved and used for the user-definable engineering units until a new ratio
is entered.
1. Use the CONVERT function (see Section 4.2) so that the 470 reports data in units of
pressure in response to an interrogation. (i.e., the transducer should not be reporting in units
of altitude.)
2. Calculate the desired conversion ratio.
3. Determine if the ratio is a multiplier or a divisor. If the ratio is in “units” per hPa, “units”
per PSI, “units” per in Hg, “units” per mbar etc., the ratio is a multiplier. If the ratio is in hPa
per “units”, PSI per “units”, in Hg per “units”, mbar per “units”, etc., the ratio is a divisor.
4. Use the CONVERT function so that the Setra 470 reports the units from which the ratio
was calculated.
5. Transmit R.
6. If the ratio is a divisor, transmit -, the minus symbol.
7. Transmit the conversion ratio.
8. Transmit U, for convert.