Control Room Equipment
This consists of a Micro-computer controlled DTMF generator, Display, Line interface and Speech circuit. This system is meant for operation over 4 Wire cable, Microwave or Optic Fiber link.

This consists of a Micro-computer controlled DTMF generator, Display, Line interface and Speech circuit. This system is meant for operation over 4 Wire cable, Microwave or Optic Fiber link. All the functions of Voice, Display, Tone generation and sequencing are handled by a micro-computer. A Table Microphone and Loud Speaker arrangement with a facility to change over to a handset is provided. The PCB's are functionally partitioned for modularity and are interconnected with minimal wiring for reliability and ease of maintenance. It works on 12 V DC supply. An optional rechargeable, maintenance-free battery pack with a charger can also be provided.


The operating console is housed in an aesthetic metal cabinet. It employs standard CCITT Dual Tone Multi-frequency codes for signaling the way stations. The desired station is called by pressing two keys on a 4x4 matrix key board, corresponding to its assigned code. It is possible to assign a maximum of 99 station codes. In addition special codes for group call, general call, and long ring are also provided. A three digit, seven segment LED display is provided to display the code being transmitted. Whenever a station is called a ring back tone is available to the controller. Communication with Way-Side Station is established through the controller's Table Mic and Loud Speaker or the Handset provided.

General Specifications:
Tummala Product Code: TEL/CRE/92
RDSO IRS Number: TC 60/2007
Operating voltage: 12 Volts DC
Current consumption: < 150 mA (Standby), < 400mA Operating

Code Generator:
Signalling Frequencies: Standard DTMF as per CCITT. 697 Hz to 1633 Hz
Signalling Level: 0 to -7 dB
Signal Duration: 200ms with 100ms inter digital pause
Number of Station Codes: 99 (01 to 99)

Speech Characteristics Receive:
Minimum I/P signal: -20 dB
Max I/P signal: +12 dB
Frequency response: ± 3 dB from 300 Hz to 3400 Hz
AGC Dynamic Range: -15 db to +10 dB
Speaker Level: Adjustable to -15dB of maximum level
Speaker output: 1 Watt Max

Speech Characteristics Trans:
Nominal Mic Output: 0 dB (Adjustable from 0 to -20 dB)
Frequency response: ± 3 dB from 300 Hz to 3400 Hz