tams elektronik GBM-8 Manual page 10

English
GBM-8. For this application the fourfold track busy indicator GBM-1**
can be used.
Due to technical principles, with (analogue) d.c. layouts the GBM-8 can
only detect vehicles driving into the supervised track sections in a
particular direction. In case the detection of vehicles from both
directions is required, the track busy indicator GBM-1** can be used.
Electric consumers located in a switched off track section can be
detected by the GBM-1 when

an additional resistor is mounted in parallel to the switch between
the switched off section and the associated input of the module and

at the same time the supply voltage is applied to the not supervised
rail sections.
Evaluation of the busy messages and transmission to digital
feedback modules
As soon as the GBM-8 detects an electric current consumer in a
connected track section, the linked output is internally connected to the
output M. This way, the output of the GBM-8 works like a switch
switching to earth.
Digital feedback modules (e.g. s88-feedback modules) can be
connected directly to the outputs. The eight outputs of the GBM-8 are
arranged so as to be connected directly to the inputs of the s88-
feedback modules S88-3** oder S88-4**.
The in- and outputs of the GBM-8 are isolated from each other by opto-
couplers. Consequently interferences are filtered out and hum loops
and fault currents are prevented effectively.
Displaying the busy messages
Especially in analogue displays, you can display the busy messages with
LEDs (together with suitable series resistors) connected to the outputs.
GBM-8
Page 10