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From this schematic, it should be clear that the command letter (c) is required, the position field
(ppppp)immediately follows it, and may have 0, 1, 2, 3, 4, or 5 characters, and there may be zero or more datum fields ( dddd), as required. For simplicity, the variable length nature of each "dddd" string is not shown [with brackets] above, but the required leading space character is shown. The position field is similarly simplified (as “ppppp”) below.
A typical UDP/IP command (contained in the data field following a UDP packet header) is also a variable length character string, but has a simpler format. Generally, it has a variable length command string (cccccc), followed by one optional datum ( dddd) field (preceded by one space character):
“cccccc[ dddd]”
Since there are only a few simple UDP/IP commands, all references to commands below should assume TCP/IP commands, unless otherwise indicated.
3.1.3.2Command Field
All NetScanner™ System models recognize a set of predefined commands. Most are TCP/IP commands having only a single alphabetic letter for a command field. These are recognized only when a formal socket connection is established with the host computer. A few are UDP/IP commands with a longer command field. These are recognized anytime the module has power applied. All commands are functionally summarized in the following sections and detailed in reference Section 3.2.
3.1.3.3Position Field
For some commands, the position field (ppppp) may be broken into other distinct independent subfields (e.g., xxyyzzf) and these subfields may or may not relate to any datum fields. In other commands, there may be a
All NetScanner™ System (Model 9816) Intelligent Pressure Scanner models may contain a maximum of sixteen (16) internal and two (2) external (rack) input channels. When commands affect certain channels scanned by the module, the position field is used to identify those channels as bits in a bit map. If a channel’s corresponding bit in the position field is set to a one (1), then that channel is affected by the command. The
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