Transmitting More Pulses, Farther

August 2015


The New OPL-4B and New OPL-8B can Send Multiple Pulses up to 65 Miles

Solid State Instruments is introducing the first SSI optical fiber pulse link capable of transmitting multiple pulses over very long distances – up to 65 miles with certain models using single-mode fiber.

Our previous optical pulse link systems, like OPL-1B, were capable of transmitting single pulse signals over such long distances, while our OPL-4C and OPL-8C systems could transmit multiple pulses of a distance of up to only 1 mile. However neither of these systems were going to work for Valley City Public Works in North Dakota when their energy supplier’s substation was recently upgraded.

In 1980, Valley City Public Works implemented a SCADA system and Remote Terminal Unit, or RTU, to help monitor and manage the city’s electrical load from one substation. In 2000, a new substation was built that also needed to be monitored. At both substations, Valley City Public Works was prohibited from installing their SCADA and RTU within the substation itself, but they could connect to the two substation KYZ pulse meters to receive the pulse data required for their load management programs. This was easily achieved by linking to the meter’s KYZ pulse outputs and then transmitting those pulses via telephone wire to the city’s RTU. By getting pulse information directly from the meters, Valley City Public Works could use the meters’ data as to determine their load management strategies.

When the substations received an upgrade this year, which essentially meant erecting new structures just a little ways away from the existing ones, it was determined that optical fibers would be installed and the use of phone lines would be eliminated. Valley City Public Works could have installed phone lines and the extra equipment required to keep their existing data transmission in place, but that option proved to be very cost prohibitive. Instead, Wayne Newton of Valley City Public Works asked SSI to provide a solution that would work with the new substation’s optical fibers and transmit multiple pulse signals about 3 miles to the city’s RTU.

In response, the engineers at SSI redesigned our OPL-4C and OPL-8C optical fiber pulse links and boosted the signal to send pulses distances far greater than 1 mile. The result is the new OPL-4B and OPL-8B optical fiber pulse link systems. Each system consists of an OPT Transmitter that is capable of receiving multiple pulses from the electric meter, then conditioning, multiplexing, and sending them to the corresponding OPR Receiver where the pulse information is validated, de-multiplexed, and implemented into the correct pulse state.

For Valley City Public Works, the first OPT-4B and OPR-4B rolled out of here at the beginning of the month. Linked by multi-mode fiber, they will be capable of sending and receiving pulses over the 3 miles from the substation to Valley City’s RTU. Additional models of the OPL-4B and OPL-8B systems are available that are capable of sending and receiving pulse information up to 65 miles using single-mode fiber. As Wayne pointed out, this capability would be ideal for rural electric companies or cooperatives with substation applications in remote areas. For advice about using the new or existing SSI optical systems for remote substation applications, or anywhere pulse information is required to travel long distances, our techs are available by phone during normal business hours at 1-970-461-9600 or 1-800-BRAYDEN, or you can email your application questions to

The OPL Family

The OPL-1B can send pulses from 1 output up to 65 miles.

The OPL-4B can send 4 multiplexed pulse signals up to 65 miles.

The OPL-4C can send 4 multiplexed pulse signals up to 1 mile.

The OPL-8B can send 8 multiplexed pulse signals up to 65 miles.

The OPL-8C can send 8 multiplexed pulse signals up to 1 mile.