simulation
Usage
>> simulation [state | period ]
Security
Unsafe and protected.
Description
This command controls whether the simulation mode is used, and if so how it will operate. It is an Unsafe command, meaning that parameters can not be modified while the instrument is enabled for logging. Modification of parameters is also Protected, meaning that the command must be immediately preceded by a permit command if parameters are to be changed.
The command's parameters are:
state [= on | off ] determines whether the channels specified in the channels option will be simulated (on), or report true measured data (off). The setting is persistent; it will remain in force from one deployment to the next. The default setting as shipped from the Factory is off.
period [= <milliseconds>] is the period in milliseconds of one full cycle of simulated values. The default value is 3600000ms, corresponding to 1 hour.
channels [ = <channel_list> ] is an option available only in firmware versions 1.150 or later, and it specifies a list of the channels that will be simulated. Each channel may be specified either by its index or by its label, but when the channel list is reported indices are always used. The channel specifiers in the list are separated by a pipe character ('|') with no spaces. The order in which channels are specified does not matter.
Derived channels can not be simulated; only measured channels may be selected. Derived channels are calculated as usual, whether the underlying measured channels are simulated or not. As shipped from the Factory all measured channels are selected by default.
There are two reserved keywords that may be used in place of a <channel_list>; all selects all measured channels for simulation, while none can be used to disable simulation for all channels.
Firmware versions prior to 1.150 always simulate all measured channels if the feature is enabled (state = on).
When state = on, the measured values from the selected channels are replaced by artificially generated values. These values follow an approximately linear ramp which travels up and down between predefined limits, taking period = <milliseconds> to complete one full cycle. All simulated channels cycle at the same rate. The channel types supported and the limits which apply are listed below.
Channel type | Minimum | Maximum | Units |
|---|---|---|---|
temperature | -5 | +35 | °C |
pressure | +10 | +2000 (1) | dbar |
conductivity | -1 | +85 | mS / cm |
PAR | -25 | +2500 | µmol / m2 / s |
turbidity | -25 | +2500 | NTU |
chlorophyll | -2 | +150 | µg / L |
o2 concentration | 0 | +450 | µM |
All other types | 25% full scale | 75% full scale | as appropriate |
Note (1): If a pressure channel's calibration coefficients indicate that 2000dbar is beyond the measurement range, a limit corresponding to the sensor's maximum output will be used instead.
The simulated values are used both for scheduled samples (whether stored in memory, streamed, or both) and for on-demand samples obtained using the fetch command. Both types of sample should confirm closely to the same linear ramp; if scheduled and on-demand samples are required simultaneously, there may be some small deviations due to the computation's attempts to satisfy both.
A logger programmed to generate simulated data can be identified in one of two ways: request the setting of the simulation state, or check the response to the id command for the indicator as shown below.
>> simulation state
<< simulation state = on|off
>> id
<< id mode = SIMULATION, model = RBRconcerto3, version = 1.000, serial = 012345, fwtype = 104
(Simulated data is enabled)
>> id
<< id model = RBRconcerto3, version = 1.000, serial = 012345, fwtype = 104
(Simulated data is disabled)Examples
>> simulation
<< simulation state = off, period = 600000
>> permit command = simulation
<< permit command = simulation
>> simulation state = on, period = 3600000
<< simulation state = on, period = 3600000
>> permit command = simulation
<< permit command = simulation
>> simulation channels = conductivity_00|temperature_00
<< simulation channels = 1|2
Errors
Error E0105 command prohibited while logging
Changes to the state or period parameters can not be made while logging is enabled.
Error E0103 protected command, use 'permit command = <command>'
Changes to the state or period parameters can not be made without issuing the command permit command = simulation immediately beforehand.
Error E0108 invalid argument to command: '<invalid-argument>'
One of the supplied parameter names or values was not valid.