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The Nets system is based on maintaining as much of an instrument's electrical definition as possible in a central database. This database is an Excel spreadsheet consisting of multiple sheets:
The cmdtm, master, component and schematic sheets are identified loosely by name. The Command and Telemetry sheet might be named "cmdtm" or "CiREX cmdtm" or even "CiREX CmdTM". The main restriction is that it must contain the string "cmdtm" independent of case, and it must not contain any of the other key strings: master, component, or schematic. The same rule applies to the other three index sheets.
The connector listings themselves are identified by the full connector name, consisting of the concatenation of the connector number (e.g. J15) and the component appreviation (e.g. MDP, hence J15MDP).
Columns are:
If column A contains a number, the row defines a command or data channel. If A contains text, the row is header text. If A is blank and column D contains text, the text in column D specifies the general category of the following data channels. [txt2ili ignores any rows that do not contain a number in column A]
The contents of the remaining columns of cmdtm depend on the channel type specified in column B. The supported types include:
[At the present time, no nets utilities make use of the signal type field. Signal types are determined by global interconnect, i.e. a signal is an analog input if and only if it is cabled to an analog input, not because cmdtm says so. This is likely to change, at least partially, with the buffer drawing application.]
The definitions for the remaining columns for analog inputs are:
E: Address is the address from which this channel can be read. [Note: At present, the address here is ignored by nets software. Like the signal type above, the address is defined by global interconnect, not by any designation here. Ideally, a subsequent development would at least verify these address definitions and flag discrepencies.]
F: Conversion is the TMC type which has been designated for collection and display of this channel.
G: Gain, if specified, is the gain on a buffer between the signal source and the A/D converter.
H: Voltage Range is the voltage range of the signal source. Note that Gain and Voltage Range both say the same thing, but the redundancy was deemed useful.
I: Telemetry Sample Rate is the collection rate as listed in the TMC source.
J: Electrical Bandwidth specifies the cutoff frequency above which no more information is available.
K: Type of Thermistor, if specified indicates that this channel is connected to a thermistor of the designated type. When specified, column L must define the pull up or pull down value.
Columns are:
There was once a column between "Connector Type" and "Alias" labeled "Location". With the unambiguous connector name convention in place, this has been deemed redundant, so column D should now be "Alias".
Columns are:
Columns are:
Columns are:
| last updated: Fri Jan 19 10:24:34 2001 | webmaster@huarp.harvard.edu |
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