Setra System Model 470 - Manual (Page 21)

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SECTION FIVE
Setup Functions
5.1 Status After Power is Applied
The Setra 470 has an internal nonvolatile memory for storing certain status and calibration
information. This memory is not erased when power is removed from the unit. Some functions
(such as baud rate, alarm setpoints, and user conversion factors) are stored in this memory.
Once they are setup they do not need to be setup again unless you wish to change the configura-
tion. However, the values of some of these functions can be changed by the user in volatile
memory while the 470 is running. After a power shut-down and restart, the values which were
stored in the nonvolatile memory are used as defaults.
On power-up:
A) Some of the functions are turned off when the power is turned on; MIN MAX tracking is off,
the ZERO/TARE value is zero, and the SEA LEVEL function is off.
B) On power-up, the 470 will report pressure in the factory default pressure units. The
only exception occurs if the user has previously executed the DISABLE UNITS function (Section
5.3) and omits the factory default pressure units from therotation. In this case, on power-up the
470 will report pressure in the next engineering units in the rotation which have not been omitted
by the user.
C) On power-up, the Station Elevation (which is set by the SETUP SEA LEVEL command) is set
to 0. Any Station Elevation entered by the user before power-down is not retained on power-up.
D) On power-up, the Stability Indicator is set to the factory default (usually 1.5 times the resolu-
tion of the display). Any Stability indicator parameter entered by the user before power-down is
not retained on power-up.
E) On power-up, the transducer reports the VERIFY message described in
Section 5.7. Next it executes an internal start-up procedure during the first thirty seconds
of operation. When the start-up procedure is complete, the transducer again reports the VERIFY
message. It is not possible to interrogate or perform any other function with the Setra 470 before
you receive the second VERIFY message.
F) On power-up, the SA, SET SETPOINTS function, the -2222S, DISABLE UNITS func-
tion, and the xUx, USER DEFINED UNITS function all default to the last value which was setup
in nonvolatile memory by the user. Any values entered by the user before power-down with the
RSA, RAM SETUP SETPOINTS, R-2222S, RAM DISABLE UNITS, and RxUx, RAM USER
DEFINED UNITS functions are not retained.
5.2 Changing the Baud Rate
The Setra Digital Pressure Transducer is capable of interfacing with a wide variety of computers
or other host devices through the RS-232C communications port. Devices which are connected
this way must be set up to communicate at the same rate of speed.
A)To change the baud rate of the Setra 470 from the factory default of 2400, use the following
procedure:
1. Use the CONVERT function (see Section 4.2) so that the 470 reportsdata in units of
pressure in response to an interrogation. (i.e., the transducer should not be reporting in units
of altitude.)