Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 12 Page 64 of 265
either a separate pedestrian phase must be configured to run in parallel with the
usual pedestrian phase, but with the required timings modified or a tactile with an
enable input must be used.
Tactiles with an enable input can be disabled during the period that the green drive
is on. Typically this is used to terminate the tactile cycle after a shorter period than
the green drive period. This prevents non-sighted pedestrians from starting to cross
near the end of the pedestrian phase green period. The enable input of the tactile
must be cabled back to the “Normally Open” output of the IO card in the cabinet.
When the IO card output is closed, the tactile will run when the green drive is on.
When the IO card output is open circuit, the tactile will not run, even if the green
drive is on.
The enable inputs of tactiles can be paralleled (either at the nearside/demand unit
or back at the controller cabinet)provided that polarity is maintained (all enable+
connected in parallel and all enable – connected in parallel) in order to save on IO
card outputs
When running a tactile with input enable facility, if the facility is not to be cabled
back to the controller cabinet, then the enable inputs of the tactile must be shorted
together using a short wire link. Without this link, the tactile will not run even if the
green drive is on.
Tactiles with an enable input and a fault output (such as the Radix ITE220)
additionally have the capability of reporting a fault back to the controller.
The fault output of the tactile is cabled back to an input on the IO card in the
controller.
The tactile will present either an open circuit or a short circuit on the fault output
under the following conditions:
ITE220 / BIC0302 Fault Output Fault Output
Tactile not powered Open-circuit
Tactile powered and stalled (held or stuck) Open-circuit
Tactile powered and motor open or short circuit Open-circuit
Tactile powered and cone able to rotate Closed-circuit
Special conditioning in the controller must discriminate between short-duration fault
conditions (such as the tactile being temporarily held stalled) and a permanent fault
that requires maintenance.
When running a tactile with fault output where the fault output is not to be cabled
back to the controller cabinet, the fault output of the controller is left open-circuit.
Tactile fault outputs must not be paralleled.