channel

Usage

>> channel <indexorlabel> [ type | module | status | settlingtime | readtime | equation | userunits | gain | availablegains | derived | label | index ]

Security

Description

Returns information about the channel at the specified <indexorlabel>. Channels can be identified either by an index (an integer) or by their label (a meaningful string, for example temperature_00 or conductivity_00). The first channel has an index of 1.

A special value of allindices or alllabels may be given for <indexorlabel> causing the requested parameters to be reported for all channels. The output for each channel is terminated by ||, except for the last channel which is terminated by a <cr><lf> pair as normal.

The following parameters give the basic information available for all channels. None of these values may be modified by end users. All parameters might be obtained using the all in lieu of parameter names.

• type is a short, pre-defined 'generic' name for the installed channel; for example:
  1. temp09  RBRduo³ temperature,
  2. pres19  RBRduo³ pressure,
  3. cond05  RBRconcerto³ marine conductivity,
     and so on. RBR Ltd continually adds support for more sensor types and variants; the Section Supported Channel Types contains a complete listing of channel types available at the time of writing this document.
     
     
• module is the internal address to which this channel responds; it is normally of no interest to end users.
  
  
• status [= <status>] is a further basic parameter which applies to all channels. It is modifiable by end users, and allows any individual channel to be turned off or on for the duration of a deployment.
  
  1. on: the channel is activated for sampling; its data will be stored in memory if appropriate, and its value will appear in streamed output if streaming is enabled. However, note that if data storage is set to Standard format (rawbin00), data is never stored for derived channels, because raw data for such channels does not exist.

  2. off: the channel is not sampled, no data will be stored in memory or streamed for this channel.
     
     

• settlingtime is the minimum power-on settling delay in milliseconds required by this channel, taking into account both the sensor and the interface electronics.
  
  
• readtime is the typical data acquisition time in milliseconds required by this channel, again taking into account both the sensor and the interface electronics.
  Most channels have a fixed, pre-determined readtime, but for some it may be variable. An example would be a channel which supports, and is configured to use, the auto-ranging feature: the readtime is longer when the channel is in auto-ranging mode than when operated in a fixed-gain mode. The logger adjusts the reported value of the readtime to reflect the operating mode and status of the channel. 
  
  
• equation is the type of formula used to convert raw data readings to physical measurement units. The values for the core equations are shown below as examples; see the section Calibration Equations and Cross-channel Dependencies for details of all supported equations.
  1. tmp  temperature
  2. lin  linear
  3. qad  quadratic polynomial
  4. cub  cubic polynomial
     
     
• userunits is a short text string giving the units in which processed data is normally reported from the logger; for example C for Celsius, V for Volts, dbar for decibars, etc. Presently this is a factory-set field representing the fundamental units in which the channel is calibrated; support for user-selectable units is planned in the future.
  
  

• derived is a flag which is either on or off to indicate whether the channel is a derived channel (on) or a measured channel (off). This is an intrinsic property of the channel type, and can not be modified: it is for information only.
  
  

• gain reports the gain setting currently in use by the channel referenced by <indexorlabel>. In addition to one of the fixed values from the list reported by the availablegains option, the response may indicate auto for auto-ranging. In this mode the channel will select the most appropriate gain setting depending on the value of the parameter being measured. Again, if the channel does not support multiple gain settings, the response is none.
  
  The gain option may also be used to set the gain used. For a fixed gain setting, the value supplied must be from the list reported by the availablegains option. For auto-ranging, use the word auto. Although they are typically whole numbers, gains are reported in a floating point format, and may be specified as such, as long as the value appears in the list of available gains.

• availablegains reports the gain settings supported by the sensor at channel <indexorlabel>. The settings are given as a list of numerical values in order of increasing gain, with a vertical bar character '|' separating the values. If the channel at <indexorlabel> does not support multiple gain settings, the response is none.

• label is a short text string without white spaces,comma, equal symbol or special character, describing the physical parameter measured (example: temperature_00). It is reported when the channel requested is referred by its index.

• index is the index of the channel. It is reported when the channel requested is referred by its label.

Examples