6
LOGIC INPUTS
The sixteen Logic Inputs are available on a rear panel 25-pin Subminiature D (female) connector. Logic Inputs allow remote control of
PMX84 input/output assignment & Logic Output functions via external circuits, such as switches, contact-closures, active driver circuits,
and/or ‘open-collector’ logic outputs. From the factory, all Logic Inputs are non-functional and may be programmed to perform functions
only through Configuration (see Configuration on pg. 10). During Configuration, each Logic Input may be defined as an individual
input/output assignment, or as multiple input/output assignments (such as a preset). Each Logic Input may also be defined with either an
‘on’, ‘off’, ‘toggle’, or ‘no operation’ function.
Furthermore, Logic Inputs may be assigned in ‘prioritized’ groups (see Global Configuration Screen on pg. 12). There are seven possible
‘priority’ group assignments: A) No Priority (all Logic Inputs at same priority level); B) One Group of Four (Logic Inputs 1~4); C) Two
Groups of Four (Logic Inputs 1~4 & 5~8); D) Three Groups of Four (Logic Inputs 1~4, 5~8, & 9~12); E) Four Groups of Four (Logic
Inputs 1~4, 5~8, 9~12, & 13~16); F) One Group of Eight (Logic Inputs 1~8); G) Two Groups of Eight (Logic Inputs 1~8 & 9~16). Within
each priority group, the lower numbered Logic Input has highest priority. Logic Inputs are affected by priority only within these groups.
Logic Inputs in one group will not have priority over Logic Inputs in another group. Likewise, Logic Inputs assigned to priority groups do not
have priority over Logic Inputs which are not assigned to priority groups. Also, within each priority group there is a ‘fall-back’ function. This
‘fall-back’ function allows a higher priority Logic Input to override a lower priority Logic Input, and then automatically revert to the lower
priority Logic Input when the higher priority Logic Input is released (assuming the lower priority Logic Input is still being activated). Since
Logic Inputs are controlled by switches, contact-closures, etc., each Logic Input is allowed two button definitions (one for switch ‘closed’
and one for switch ‘open’). Therefore, button definitions are also available for when certain groups of Logic Inputs are all ‘open’. This is
very effective for creating an additional ‘fall-back’ priority level. For example, when all of the Logic Input 1~4 priority group are ‘open’ (no
paging), a special button definition may be activated which selects a ‘fall-back’ assignment (such as background music).
Logic Inputs may also be set for ‘normal’ or ‘binary’ modes of operation. The ‘binary’ mode reconfigures Logic Inputs 9~12 for ‘room
combining’ applications, utilizing one Logic Input (switch) for each room partition. This supports up to four rooms, with sixteen possible
combinations of ‘open’ or ‘closed’ partitions. Under these circumstances, button definitions are created which perform the appropriate
input/output assignments when specific room partitions are moved (switches ‘opened’). In Binary mode, Logic Inputs 1~8 operate
normally, however, Logic Inputs 13~16 are unused (disabled). Files are available for downloading to the PMX84, which represent typical
uses of Logic Input Priority & Logic Input Mode, for page routing & room combining applications (see Application on pgs. 16~21).
When nothing is connected to a Logic Input, an internal pull-up resistor keeps it at a ‘high’ idle state (+5.0 VDC). The Logic Input is
activated when its input goes ‘low’ (less than +0.8 VDC), and is de-activated when its input goes ‘high’ (greater than +2.4 VDC). A Logic
Input is controlled in one of three ways: 1) Use an NPN style ‘open-collector’ logic output from an external device (such as an AGII
Autogate or DRC 4+4 Digital Remote Control) to short the Logic Input to ground. 2) Use a switch, relay, or other contact-closure (such as
from a third-party controller) to short the Logic Input to ground. 3) Use an active TTL output driver circuit (such as from a third-party
controller) to actively drive the Logic Input to a ‘high’ or ‘low’ state.
Multiple contact-closures or ‘open-collector’ logic outputs or may be wired in parallel to a single Logic Input (see diagrams on next page).
Likewise, a single contact-closure or ‘open-collector’ logic output may be wired in parallel to multiple Logic Inputs. In some circumstances,
a diode matrix may be necessary to isolate multiple switches which are controlling similar groups of Logic Inputs. However, these
circumstances may be rare, since each individual Logic Input may be defined to perform multiple funtions. Logic Outputs and contact-
closures should be rated for at least 5 Volts / 1mA operation. Low-current / dry-contact closures are recommended for reliability. Active
output driver circuits should not exceed a signal range of 0~5 Volts DC, and should have a minimum pulse width of 100 milli-seconds.
Logic Input impedances are approximately 10k ohms.
