Signals on the Meramec Valley & Pacific are driven by CTI Electronics circuit boards. Each Signalman board will power up to 16 leds. The CTI system interfaces with the computer and works with the Railroad & Company TrainController Silver software, which allows for the connection of multiple systems.
Lenz block detectors are used to detect block occupancy. This information is reported to the TrainController software, which then uses this data to pass the correct signal indication to the CTI system.
Most of the signals on the layout are manufactured by Tomar. There are also some Oregan Rail signals which come as kits and require assembly, and even a few signals I’ve made from brass tubing and other parts. All signals on the Eagle River Division layout are wired for Common Anode. It works best if all your signals are of the same polarity – either common anode or common cathode. CTI Signalman boards are available for both.
CTI also makes a Signalman card for bipolar LEDs. These cards are made to work with 2-lead bipolar LEDs (not the 3-lead common-cathode or common-anode LEDs). A number of these searchlight signals were recently added to the upper level of the layout, and are driven by these CTI bi-polar type cards.