here is a Polara EN4 Pedestrian push button i have setup to place calls to my traffic cabinet.
this model has been discontinued from there line of Pedestrian push buttons, EN4 uses 4 wires to communicate with the Pedestrian signal, the small board is mounted inside the Pedestrian Signal head and send data and power through the 4 wires to the push button, the button itself connects via 2 wires to the traffic cabinet to place a call for that Crosswalk. there is another Polara button called EN2 and only uses 2 wires to send power and data to a box inside the traffic cabinet, these buttons are programmable for certain functions, example- volume, street name, direction announcement, count down or other beeps or pings