Figure - Honeywell PPT User Manual

Table 5.3—Command List Notes
(1) The C= and D= commands do not change the mode of operation but do provide a user supplied
power-up message if configured using the MO command.
(2) The IN command does not change the operating parameters stored in RAM, but it does stop
continuous readings (P2, P4, T2, T4 commands). If the IN=RESET command is sent, then any
parameters that were stored in RAM, and were not stored in the EEPROM with a SP command,
will default to the last stored EEPROM value. This may cause a change in the operational
parameters as well as a configuration change.
(3) The P2, P4, T2, and T4 commands do not change the operating parameters, only activate
continuous readings. The N= and '~' commands do not change any operating parameter values
only the DAC analog output voltage.
(4) When an information request command is sent to a group or global address, the PPTs do not
respond sequentially. That is, the command is returned to the host processor before the replies
from the PPTs. Also, these commands require more time for execution, often requiring EEPROM
reads and/or writes, so responses from more than one PPT are not received in any guaranteed
order. During the execution of one of these commands, if another command is received that is an
"After" type, whether globally, group, or individually addressed, the received command is
rejected and the command read status error (see RS command) is set.
(5) These commands may cause sequential responses from any, all or none of the addressed units. A
sequential response is when the PPT reply is sent before the global or group command through
the network. See the individual command descriptions for detailed information.
(6) These commands only require a write enable (WE) when used in the action directing form. For
these commands the WE command provides a single occurrence write enable for RAM update.
That is, only the next instruction is written to RAM. The WE=RAM
ous write enables for RAM for multiple command updates. The continuous RAM enable is active
until a WE is sent.
(7) The N= command requires an NE command enable when used to send information. The NE
command provides single occurrence write enable for analog control. The NE=DAC command
can be used to provide continuous write enable for analog control.
(8) The '~' command requires an NE command enable. The NE command form provides single
occurrence write enable and the NE=DAC command form provides continuous write enable.
The NE=CKS command form provides continuous write enable and requires that the '~' com-
mand contain a cyclic checksum.
(9) These commands terminate an active continuous reading command (P2, P4, T2, T4) and
initiate the new one.
(10) These commands automatically write to the EEPROM when they are used in the action direct-
ing form, which must be preceded by a WE command.
(11) These commands can be used to change RAM contents which can then be written to the
EEPROM using the SP=ALL command.
(12) The DA command does not write to the DAC but it does allow the DAC to be controlled by the
PPT input pressure value or by a digital value applied by the N= command.
(13) These commands only write to the DAC when used in the action directing form.
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command provides continu-