SUMO
Simulation of Urban MObility

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# TraCI/Induction Loop Value Retrieval

## Command 0xa0: Get Induction Loop Variable

ubyte | string
Variable | Induction Loop ID
--- | ---

Asks for the value of a certain variable of the named induction loop (e1 detector). The value returned is the state of the asked variable/value within the last simulation step. Please note that for asking values from your induction loops with TraCI, you have to:

- define them
- set their frequency to 1s

The following variable values can be retrieved, the type of the return value is also shown in the table.

Overview Retrievable Induction Loop Variables
Variable | ValueType | Description
--- | --- | ---
id list (0x00) | stringList | Returns a list of ids of all induction loops within the scenario (the given Induction Loop ID is ignored)
position (0x42) | double | Returns the position of the induction loop at it's lane, counted from the lane's begin, in meters.
lane ID (0x51) | string | Returns the ID of the lane the induction loop is placed at.
count (0x01) | int | Returns the number of induction loops within the scenario (the given Induction Loop ID is ignored)
last step vehicle number (0x10) | integer | Returns the number of vehicles that were on the named induction loop within the last simulation step [#]; Note: This value corresponds to the nVehEntered measure of induction loops.
last step mean speed (0x11) | double | Returns the mean speed of vehicles that were on the named induction loop within the last simulation step [m/s]
last step vehicle ids (0x12) | stringList | Returns the list of ids of vehicles that were on the named induction loop in the last simulation step
last step occupancy (0x13) | double | Returns the percentage of time the detector was occupied by a vehicle [%]
last step mean vehicle length (0x15) | double | The mean length of vehicles which were on the detector in the last step [m]
last step's time since last detection (0x16) | double | The time since last detection [s]
last step's vehicle data (0x17) | complex (see below) | A complex structure containing several information about vehicles which passed the detector

## Response 0xb0: Induction Loop Variable

ubyte | string | ubyte | <return_type>
Variable | Induction Loop ID | Return type of the variable | <VARIABLE_VALUE>
--- | --- | --- | ---

The respond to a "Command Get Induction Loop Variable".

### Response to "last step's vehicle data" (0x17)

The return type is "complex", the following fields are:

ubyte | int | <INFORMATION_PACKET> | ... | <INFORMATION_PACKET>
"int" | number of information packets | <INFORMATION_PACKET> | ... | <INFORMATION_PACKET>
--- | --- | --- | --- | ---

Where each information packet looks like:

ubyte | string | ubyte | double | ubyte | double | ubyte | double | ubyte | string
"string" | Vehicle ID | "double" | Vehicle Length | "double" | Entry Time [s] | "double" | Leave Time [s] | "string" | Vehicle Type ID
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---

## Notes

- You can find some further description on induction loops

This page was last modified on 28 October 2011, at 11:57.