Honeywell PPT User Manual page 58

L = Lowest Analog Output Voltage
Set the DAC Low analog output voltage zero reading for absolute and gauge units and most negative
reading for differential units. The input is a value from 0 to 99% of 5 volts, or 50 millivolts per count.
An L= inquiry reads the value in 50 millivolt counts. This command is used in conjunction with the
H=, and AN commands to customize the range of the PPT analog voltage output –see Figure 4.4. If
there is an input error, then the command error flag in the RS command will be set and no change
will occur. (Default: L=0 )
Note: See the H= command for setting the high, full scale, analog output voltage. See the AN com-
mand for enabling and disabling the H= and L= settings. If L= value • H= value, then no change will
occur and an RS command error will result.
Inquiry: *ddL=
Action: *ddWE
*ddL=pp
pp 0 - 99 This number sets the zero reading for absolute and gauge units and the FS negative
reading for differential units as an integer percentage of 5.00 volts. It can also be thought
of as a multiplier in 50 millivolt increments. As an example, L=15 corresponds to a zero
reading voltage of 0.75 volts (15 x 50mV or 15% of 5.00V). For L=0, the low voltage will be
0V. For L>99, the low voltage will be 4.95V.
M = Maximum Customized Full Scale
This command identifies the Maximum full scale pressure, in psi units, that can be user customized
(see F= command). This value is fixed at the factory and corresponds to the full scale reference value
for accuracy and error determination. If the response has an '!' character instead of '=', there was an
EEPROM parity error.
Inquiry: M
* d d
RS-485 type only
This command is used to select the PPT alternate message header set of non-printing characters.
This can be used when there is a conflict between the standard PPT message headers and the
message characters used by some other components that share the bus.
To change from standard to alternate headers:
Action: *ddWE
*dd M=ALT
To change from alternate to standard headers:
Action: (ctrl \) ddWE
(ctrl \) ddM=ALT
Standard Header
Note: For example, the designator (ctrl \) indicates that the control key, "ctrl", is held down while
the backslash key, "\", is typed.
Alternate Header
* becomes
$ becomes
~ becomes
# becomes
{ becomes
} becomes
! becomes
@ becomes
(1)
EEPROM Store: *ddWE
EEPROM Store: (ctrl \) ddWE
EEPROM Store: *ddWE
ASCII Name
ctrl \ FS
ctrl ] GS
ctrl ^ RS
ctrl _ US
ctrl Q DC1
ctrl R DC2
ctrl S DC3
ctrl T DC4
See Table 9.2 for ASCII values.
5 2
*ddSP=ALL
(ctrl \) ddSP=ALL
*ddSP=ALL
(1)