Lowrance LSS-1 transducer

[Clembuilt]

I recently purchased a 2009 Z7 that has a Lawrance StructureScan LSS-1 module with a HDS-7 control head. When the power switch is in the off position, for the transducer, I obviously have no down or side scan. However, there control screen continues to show water temp, depth and speed. Does this system work with two separate transducers? The prior owner does remember the specifics on how it all was installed and I cannot find any information on-line. Thanks for any input...