LED Control
25
One Wire (Yellow)
With one wire, the Yellow drive is wired as shown in Figure 14.
The Yellow LED drive gets inverted in the read head resulting in a Red
LED when the signal is low and a Green LED when the signal is high. If
the Yellow LED drive is oscillating, the Red and Green LEDs will be
oscillating and will appear to the human eye that the LED is Yellow. The
RM-4E will oscillate the Yellow drive at 1 KHz when a Yellow LED
display is required.
FIGURE 14. External Bi-color (1 wire)
Special RM-4E 1-Wire
LED Control
Setting both SW5-3 and SW5-2 On results in a special RM-4E legacy mode
that is equivalent to the 1-wire Bi-color mode on earlier versions of the
RM-4E.
In the standard 1-wire Yellow drive connection, the drive will oscillate,
resulting in the appearance of a Yellow LED. In the special mode, the
drive does not oscillate and there is no Yellow indication.
