Solution - When the SLC loops are wired Class A, an open on the positve (S+) loop wiring will cause the the panel to display "Open SLC1 or Open SLC 2".
*Note -This is a latching fault condition and will not clear until RESET is pressed.**
To find an intermittent open, program the SLC to be a SINGLE CLASS B LOOP and remove the wires from the return loop S2+ and SC2-. When the fault occurs again all the points beyond the break will report as missing.