Turnout display units
The signal lamps show the immediate status of the turnout, i.e. whether the turnout is being rebuilt or is being rebuilt, if it is blocked (the selected direction is flashing) or if it is faulty. Signal lamps are designed not to be confused with traffic lights. They communicate with the switch cabinet control unit via a serial line with current loop or via RS 485 bus (or via single-bit inputs - on request).
Lamp states - basic direction signalling:
The standard mode of information displayed on the BSV-LM 03 or BSV-LM 04 lamp is semaphore mode, where the states or directions of the turnout settings are displayed:
- Straight direction,
- direction to right turn,
- left turn direction,
- the queue dot (blue or white) indicates the existence of the trolleybus order in the queue - it is always accompanied by the indication of the current turnout setting (left, straight, right, fault). It is used for trolleybuses where it allows more than one trolleybus to pass on one "green" and after the first trolleybus leaves the switch is repositioned for the passage of the second trolleybus. The queue dot is lit when there are two or more trolleybuses in the monitored section.
Lamp conditions - signalling of error conditions:
These conditions occur when a turnout malfunctions or if there are problems with the turnout alignment. Possible error conditions:
- No entry to a turnout that has open switch contacts or broken wires,
- no entry to a switch - the contacts are facing the opposite direction, i.e. each trolleybus switch is set differently.
Lamp states - dynamic events during switching:
Flashing direction symbol means switch blocking for the building time. During this time, the turnout cannot be rebuilt or the rebuild instruction cannot be entered.
- Flashing direction symbol to the right during a right hand stop,
- the left direction symbol flashes when building on the left,
- the direction symbol flashes straight when setting straight,
- blinking dot - the turnout is changing (state between changing the position of the contacts when changing direction)