Setra System Model 470 - Manual (Page 23)

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5. Transmit a sequence of 1’s and 0’s in which each 1 or 0 corresponds to an engineering
unit of measure in the sequence listed below. Transmit a 1 to enable, or a 0 to disable,
selection of the corresponding units. The sequence of units is:
“units” (the user programmable units)
hPa
PSI
mbar
mm Hg
in Hg
mm H20
in H20
feet
meters
Each 1 or 0 must be followed by an S, for SETUP.
For example, to set up the CONVERT function so that it changes the units in which data is
reported directly from “in Hg” to “feet” and back again, eliminate all other units from the
sequence by transmitting the following command:
-2222SS 0S 0S 0S 0S 0S 1S 0S 0S 1S 0S
6. At lease one pressure unit must be enabled. If you attempt to disable all of the units of
pressure, the transducer will ignore the entire sequence.
7. If the 470 responds “PROTEC”, set the program enable switch to “OFF”. Transmit C, for
CLEAR, to resume operation.
5.4 Disabling Engineering Units in Volatile Memory
As in the previous section, the Setra 470 can disable one or more of the built-in engineering units
accessed by the CONVERT function. This function changes the setting in volatile memory only.
On power-up, the setting defaults to that stored in nonvolatile memory by the (DISABLE UNITS)
code function -2222SS (Section 5.3).
Use the following procedure to enable and disable selection of any of the engineering units by the
CONVERT function.
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. Transmit R-2222SS, the Engineering Units access code.