Pressure Systems 9022 - Manual (Page 35)

Pressure Systems, Inc. NetScanner™ System (9016, 9021, & 9022) User’s Manual
www.PressureSystems.com 3 - 5
3.1.2.5 Format Field
Some commands, that either send data to a module (as command parameters), or cause the host to
receive data (via command’s response), have an extra format parameter (f digit) appended to (or
specified in) the position field. This parameter, when specified (or implied by default), governs how
internal data are converted to/from external (user-visible) form.
!
The most common format (f=0) causes each datum (in command or response) to be
represented as printable ASCII numbers externally (with optional sign and decimal point as
needed). Internally, the module sets/obtains each converted datum to/from a single precision
binary (32-bit) IEEE float.
! Some formats (f=1, 2, 5) encode/decode the internal binary format to/from ASCII
hexadecimal external form. Some of these “hex dump” formats provide an external hex bit
map of the internal binary value (float or integer as appropriate). Format 5 may
encode/decode the internal float value to/from an intermediate scaled binary integer (e.g.,
float value * 1000 into integer, then to/from a hex bit map).
! Two special “binary dump” formats (f=7 and f=8) may be used by some commands to
accept/return binary data directly from/to the user’s command/response. Such values are not
user-readable in their external form, but are directly machine readable and provide highly
compact storage without any accuracy loss due to formatting. Use of these formats allows
both the module and host program to operate in their most efficient, low overhead mode.
Format 7 returns the most significant byte first (i.e., big endian). Format 8 returns the least
significant byte first (i.e., little endian).
See the individual command descriptions for the formats a particular command recognizes.
3.1.3 Responses
Four (4) types of responses can be returned from a NetScanner ™ System Intelligent Pressure
Scanner module:
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an Error response,
! an Acknowledge response,
! an Acknowledge with Data response, or
! a Network Query response.
The first three may be returned by TCP/IP commands, the latter from a UDP/IP command.