TT-43.1A and TT-43.1B Electronic recording units

The display and control units allow for:

• analog velocity display in the range 0 to 160 km/hour or in a range as specified by the user, allowing for regulation of the scale illumination brightness. The scale is fitted with a red scale-line indicating maximal design speed for the given vehicle type;
• digital display of velocity on the control unit display,
• display of the value of pressure in the brake piping on the control unit display,
• signalling of a loss of  recording by a LED diode (signalises a failure of the recording tachometer or an incorrectly inserted card),
• signalling of filling up of the memory capacity, by a LED diode,
• signalling of a failure of the sensor by a LED diode (signalises a fault of one or more phases of the velocity sensor),
• signalling of exceeding of the maximal allowable velocity of the vehicle by a LED diode,

Input of parameters into the recording unit using a keyboard. There are two levels for the input of parameters:

• by the engine driver – free access to inputting parameters into the recording tachometer by the engine driver,
• by the maintenance staff – coded access only for the maintenance staff purposes

Multi-functional display (allowing for regulation of its brightness) which allows for recovering and displaying the following information:

• real time (basic mode of the display),
• date – automatic mode allowing for adjustment of the time by the maintenance or via the vehicle bus-bar,
• total distance travelled in km – automatic reading up of the travelled distance allowing for adjustment by the maintenance,
• daily distance travelled in metres, may be reset to zero by the engine driver,
• statistical registration number of the engine driver,
• number of the train,
• departure station for the given railway section or the point of changing of the engine crew,
• train weight,
• braking mode,
• braking power rate,
• statistical registration number of the vehicle,
• home service station of the vehicle,
• diameter of vehicle wheel set in the range of 750 to 900 mm or as specified by the user,
• max. allowable vehicle speed,
• diagnostic data – checking of correct function of the connected signals and equipment, probable cause of failure of the assembly etc.,
• manufacturing number of the recording tachometer assembly.

The velocity sensor is a four-phase optical sensor – two phases are sufficient to sense the vehicle speed and distinguish the direction of driving; the remaining two phases are used as spare. In case of a failure of any of these phases, this failure is signalled on the display unit by a LED diode; however, the functionality of the unit is fully retained. The assembly is fully functional also in case of a failure of two phases of the sensor.

The velocity sensor is located on the bearings housing of the wheel set; it’s mechanical dimensions allow for replacing it by velocity sensors supplied by Metra and Hasler. The mechanical design is fit for operation under heavy service conditions.

The velocity sensor is fed from the source that is a part of the recording unit of the recording tachometer.

Sensor of air pressure in the brake piping – the temperature sensor DMP 331 may be used for the unit, or another sensor based on an agreement.

The cables for connecting the velocity sensor to the recording unit are (for the purpose of an easy mounting and dismounting of the sensor during operation) divided in two parts. The individual parts are to be interconnected using a connection box or using a connector supplied by the manufacturer of the recording tachometer. The length of the cables from the velocity sensor to the connection box (or connector) is assumed to be approx. 1.5 m, and the length from the connection box (or connector) to the recording unit approx. 4 m (depending on vehicle type). Based on an agreement with the manufacturer, the cables can be supplied in lengths according to the user requirements.