It's an LS1000 model. It operated with either the RC-7 or RC-15 cell (SC-48 or SC-60, respectively). These first came out around 1992 and phased out around 2000-2001.
The LS1500 had a time clock mechanism on the right panel.
The LS2000 was a two-time clock, inhouse hardwired control panel system.
Positions 10 and 11 were the same.
I think if you opened the unit, on the right side, there may be a serial number written in black marker.
These were the first models made after we bought Lectranator in 1992.