VISSIM 5.30-05 User Manual

6 The Traffic Network
Each connection is directed from an output channel
number of one SC to an input channel number of
another SC. Data written by the control program to
an output channel is transmitted in the simulation
second to the connected input channel and can be
read from its control program.
Example (using controller type VAP)
Define the SC communication from SC 1, channel 7 to SC 3, channel 5. In
the control logic the following commands can be used to send and receive
data:
► Within the control logic of SC 1 the command below will set the output
value of channel 7 to 1:
Marker_Put( 7, 1 )
► One simulation second later, the control logic of SC 3 can read this value
through channel 5 using the following command:
Value := Marker_Get( 5 )
The user-defined variable “Value” will then be set to 1 and can be used
for subsequent program commands.
6.7.7 Railroad Block Signals
Railroad block signals can be edited only directly in the VISSIM network file
(INP). A signal head that is defined as a block signal ("Blocksicherung") does
not belong to a signal group or signal controller but is switched according to
the state of the next two signal groups downstream.
Every block signal determines once per time step the status of the next two
adjacent blocks downstream (a block is defined as the area between two
block signals). The signal appears as follows:
► Red in case of a vehicle occupying the next immediate block
downstream
► Amber if the next block is unoccupied and the following block is
occupied by a vehicle
► Green if both downstream blocks are empty
All vehicles passing a block signal displaying amber receive the associated
maximum speed until they approach a block signal displaying green.
Railroad block signals count normal signal heads as block delimiters but do
not influence the states of those signals.
The definition of a railroad block signal will look like the line below:
336 VISSIM 5.30-05 © PTV AG 2011