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FSK Teleprotection Terminal


The PTR-1500 is a four channel audio tone teleprotection terminal used for high speed tripping in protective relaying schemes for electric power generation and transmission. The PTR-1500 can communicate over a voice grade telecommunications medium (i.e. carrier, wire line, metallic pairs and microwave) or over fiber optic lines. The PTR-1500 has been optimized for high speed, dependability and security. Single and dual channel FSK modulation techniques are used in conjunction with digital differential Guard/Trip energy sensing. The Digital Signal Processing (DSP) technology used to generate transmitter frequency, establish receiver frequency discrimination and manage all channel filtering is crystal controlled. This design provides a high level of stability, which overcomes the drift with temperature and age problem encountered with analog methods. The design of the PTR-1500 allows for on-board programming without the need of an external programmer or laptop. Operating characteristics of the PTR-1500 are controlled by firmware. Parameter changes are accomplished by changing DIP switch settings. Frequencies, channel bandwidths, communications protocols and logic modes are all programmable.


The PTR-1500 teleprotection terminal is designed as a four channel communications system that can operate in three different modes depending on how the Logic Module is programmed.

Dual Channel

Two frequencies are always generated by the Transmitter, either two Guard tones or two Trip tones. Both Trip frequencies are required in order for a Trip to be output. The use of two frequencies for Guard and Trip signals dramatically increases the security of the system.

Single Channel

One frequency is generated by the Transmitter, either a Guard or Trip tone. When the Trip tone is received the Trip is output.

Dual Independent

Two frequencies are generated by the Transmitter. The system operates as two single channel units simultaneously. When the Trip frequency is received the corresponding Trip is output. Each Trip input will operate independently of the other.

Because the PTR-1500 is a four channel unit, it can operate 2 of the above logic schemes independently in the same unit. The 2 “halves” of the unit need not be the same.


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