7
Caution Power
Cycling
Power supplies with large capacitive outputs may cause problems if
power is cycled within a short time period. The power supply’s
capacitor will supply enough current to keep the microprocessor
running for a few minutes but not enough to keep the display active. If
full power is restored during that time the microprocessor may not
initialize the display module. The result is that the display will remain
blank or show just the cursor in the upper left-hand corner and the rest
of the unit will be fully functional.
To remedy this problem run power to the unit through a “seal in”
circuit or remove the capacitor (the MMI does not mind if power is
unregulated) or wait sufficient time between power cycles.
Caution Wire
Routing
Wire lengths should be minimized (Maximum 1600' (500 m)
shielded, 1000' (300 m) unshielded).
Wires should be run in pairs with a neutral or common paired with a
hot or signal line.
If wiring is to be exposed to lightning or surges, use appropriate
surge suppression devices.
Keep AC, high energy, and rapidly switching DC wiring
separate from signal wires.
Equip ungrounded DC supplies with a resistor and capacitor in parallel
to earth ground. This provides a path for static and high frequency
dissipation. Typical values to use are 1MOhm and 4700pF.
Connection
To make a connection, strip about 1/4" of insulation off the end of the wire, turn the connector
screw counterclockwise until the gap is wide open, insert the wire all the way in, and turn the screw
clockwise until it’s tight.
Connect positive DC line to terminal 1 and the DC ground to terminal 2.
Summary of Contents for MMI-1 Series
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