Single Section Digital Axle Counter DACF 700a/ AP™

The Single Section Digital Axle Counter is the latest model of Axle Counters for detecting the presence of a train in any specified track section based on principle of axle counting. The system can be used for all type of track circuiting/ block proving application in railways.

The DACF-700A / AP a track side equipment comprises of Axle Detectors and Electronic counting units connected by means of one pair of cable installed at both limits of track section. When train passes it counts and stores the number of axles by means of software at both ends. The counts are compared and when counts become equal, decision is given to drive the vital relay to pick up and track section is shown clear. The system is used more advantageously for monitoring the complete section.

Its application includes:

1.	Block Working	4.	Loop Line
2.	Intermediate Block Signaling	5.	Main Line
3.	Auto Signaling	6.	Platform Lines

Components Of DACF 700A/AP:

1. Tx & Rx Coil Axle Detectors - 2 Nos.
2. SSDAC Counting Unit - 2 Nos.
3. Reset Box - 2 Nos.
4. Vital Relay Box - 2 Nos.

The Station Master is provided with LED indication of track clear /occupied and reset facility for maintenance.

Features:

1. Trackside electronic counting equipment.
2. Web type axle detectors.
3. Compatible with 90 R,52 kg & 60 kg rail profiles.
4. Detection of all wheels with diameter > 400 mm.
5. Track clear / occupied at both stations.
6. Normal operation during water logging on rails.
7. Easy to install,commission and maintain.

Principle Of Working:

The Single Section Digital Axle Counter DACF 700A/AP comprises of Axle detectors and track side Electronic Counting Unit linked by connecting cables. It is installed at both limits of track section. The Axle Detectors operate on high frequency (21K Hz & 23 KHz) according to the proven method of electromagnetic wheel detection. When a train wheel enters in between the detectors, it influences the electromagnetic field and the wheel is detected. The detected wheels of a train are converted into pulses and these pulses are counted at the entry and exit of the track section. The stored counts are exchanged by telegram packets between the units. The track clear decision is arrived after the counts are equal and Vital Relay is driven to pick up for Signaling the next train, otherwise the track is shown as occupied.
Design:

1. Designed as per CENELEC, SIL- 4 (European standards).
2. 21 K Hz & 23 K Hz high frequency Axle detectors.
3. Micro controller based design with 2 out of 2 decision.
4. Counting through software.
5. Cyclic Redundancy check (CRC).
6. V.21 modem communication (2 wire).
7. Compatible with OFC & Radio.
8. Opto Isolated relay drive for Q type 24V, 1000 ohm.
9. Fail safety tests conducted and found OK.
10. MTBF is greater than 15 years.

Specification:

1. Specification No. RDSO/SPN/177/2003.

Approved by:

R D S O, LUCKNOW

Reliability:

1. Reliable operation for short detection times.
2. Immune to traction return currents, magnetic disturbances and other interference form Signaling relays.
3. Error free operation over large temperature range (Zero degree Celsius to +70 degree Celsius) even in conditions of extreme humidity.
4. Protected against the effects of lightning.

Supportive Equipment Required:

1. 24V, 40 AH Battery or 24V, 5 Amp from IPS.
2. 24V, 5A Battery Charger.
3. 4 Quad Cable
4. Power Cable, 25 Sq. mm. 'Al', 2 Core
5. Signaling Cable, 1.5 Sq. mm.
6. Q type, 24V, 1000 Ohm, 6F/6B Relays.

Turnkey :

CEL has been successfully manufacturing the Railway Signaling equipment for more than 20 years and providing turnkey solutions for track circuiting, Single line and Double line block working systems to Indian Railways. CEL is equipped for manufacturing , supply and installation of Single Section Digital Axle Counter on turnkey basis.