Instruction manual

ACU-1000 Operations Manual
7-2
7.2 PSM-1A replaces PSM-1
The PSM-1A was created to comply with changes to US and European Safety certification
requirements related to terminal and PCB trace spacings.
Main compatibility notes:
• The PSM-1A can be plugged into previous versions of the ACU-1000 chassis (those
shipped with a PSM-1), and will function properly.
• The PSM-1 cannot be plugged into a newer chassis (those shipped with a PSM-1A).
The PSM-1 will not function properly in the newer chassis, and to prevent confusion,
the newer chassis were designed to prevent the module from being inserted fully in the
chassis.
• The PSM-1A allowed unit operation from a +24 VDC (nominal) power supply. This
feature was removed from the PSM-1A due to lack of space.
7.3 HSP-2A replaces HSP-2
The HSP-2A was created to add new features (mainly to improve the ability to interface the
HSP-2 to other parts of a Wide Area Interoperability System) and also to deal with component
obsolescence. The HSP-2A also combines all circuitry onto a single PCB, making voice
prompt memory IC changes much easier.
Main compatibility notes:
• The HSP-2 did not have microphone input level adjustment jumpers.
• The PTT input circuit of the HSP-2A is more “standardized” for operation with a wider
range of headsets. It is an active low input on the HSP-2A, while the HSP-2 was active
high.
• The associated rear panel D15 connector (P13) pinout in the HSP-2A can be configured
to mimic the P1 through P12 pinout, allowing radios and NXU-2A units to be
connected to P13 using standard interface cables.
o Internal jumper JP10 of the HSP-2A allows the External Speaker output to be
configured instead as a ground connection, the same as P1 through P12 for a
single-ended audio ground connection.
o With the HSP-2A, pin 13 is normally configured as a COR input (like P1-P12),
but may be configured as /AUX In 3 as it is in all HSP-2 modules.