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Phone:
800-324-8388 970-249-6129 Fax: 970-249-8919 |
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Phone:
800-324-8388 970-249-6129 Fax: 970-249-8919 |
Dial-Up Communications
Da-Tel provides several solutions to automated data collection and control schemes over a dial-up telephone network. These devices are compatible with all power systems and are transient protected for harsh environments.
Private Automated Business Exchange (PABX), Model G-8820B |
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As more smart terminals are being installed in substations, a conflict has arisen. When a master computer dials and accesses the substation, to which terminal should the call be directed? The simple solution is to add telephone lines, one per each smart terminal. However, this is not cost effective when considering the monthly telephone service billing.
To solve the problem, Da-Tel Research Company has developed a small, automatic device to direct incoming calls to the correct smart terminal. The device is the G-8820B PABX.
Model G-8820B (includes Power Supply and Single Rack Space 19" Shelf)
Programmable Audio Line Switch, Model G-9420 |
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The Programmable Audio Line Switch is a device that allows a caller to multiplex up to 8 telephone lines onto a single 2-wire pair. Many features are programmable with a touch tone phone to allow custom configurations. IEEE surge and lightning protection and station battery powered make the G-9420 ideal for use in harsh environments such as the substation.
Model G-9420 - 1 (includes Power Supply and Single Rack Space 19" Shelf)
Expandable PABX, Model G-9020 |
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The G-9020 Expandable PABX System is a full featured PABX system specifically designed to maximize the use of a single dial-network telephone circuit in the substation.
The G-9020 provides features in addition to its basic ability to switch the telephone line from one audio port to another and from one smart terminal to another. The G-9020 system has enhanced diagnostic, security and indication features; and additional modules expand the system in increments of 8 audio ports to a maximum capacity of 64.
Model G-9020 Expandable PABX (includes 19" 3U Shelf and Power Supply)
Telco Interface Module, Model G-9813 |
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The major cost of telemetering over the years is usually the cost of the telephone lines, microwave or fiber optic connections. Many applications do not require a full time connection. The dial-up time-sharing telephone system offers a low cost connection wherever a few calls per day can pull in the salient information on remote monitoring and control equipment. Examples of dial-up time-sharing application are lake levels, water flow, tank storage, records of power generation, power usage and smart monitoring and control equipment which store data that can be down loaded. Deregulation also requires monitoring of peak power.
The G-9813 Telco Interface Module is used to interface a dial-up telephone line to a telemetering system. This module allows the transmitting side of the remote telemeter to be monitored and receiving side to be controlled using FSK tones and modems. A typical system is shown in the block diagram.
The composite peak voltage output level of the telemetering system is set for -9dbm single frequency peaks. The telephone company uses signal frequencies in the bandwidth of 2450 to 2750Hz to control the dial-up system and the frequencies below 800Hz are used by dial tones. These frequencies are not used for telemetering.
The G-9813 Telco Interface Module consists of a ring detector circuit and a latch circuit to control ON-HOOK and OFF-HOOK conditions along with a dial-tone detector to reset the latch to ON-HOOK on completion of a call. This module has been FCC part 68 registered #IDF USA-36002-OT-N.
POWER MONITORING APPLICATION WITH A DIAL-UP SYSTEM |
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Monitoring power into factories via the telephone over a dial-up telephone network can be helpful to both the factories and the power companies. Deregulation is normally associated with high costs of power during peak power usage from the grid. Responding to these peak power costs will allow the generators to stay on line and not overload.
Da-Tel Research Co. Telemeter Systems can bring in and display accurate readings of power to allow the adjustment of the load to fall within your grid lines. A typical system that uses the dial-up telephone lines to telemeter kilowatts (or megawatts) to a control area is shown below. Other communication lines such as dedicated telephone lines, fiber optic lines, microwave links and radio can be used as fits the situation.
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