First Isaac16 EDU, Reference Manual, Page: 6 / 12

Innovation First, Inc. EDU-RC & Motherboard Reference Guide
11.8.2002 www.InnovationFirst.com Page 6
6. RELAY Outputs
The Isaac16 EDU Motherboard has four 4-pin RELAY connectors (abbreviated RLY). The Relay
outputs are most commonly used to drive Multi-Speed Motors. These outputs can only drive the Multi-
Speed Motors in Full Forward (clockwise), Full Reverse (counter-clockwise), or Off. The Multi-Speed
Motors can be connected directly to the Relay outputs. Be sure to connect the cable so the black wire is
on the indicated pin (on the right side of the connector).
The Relay outputs can also drive Spike Relay Modules. The Spike Relays can be connected directly to
the Relay outputs. Use a 3-wire PWM/Relay extension cable to connect a Spike to one of the Relay
outputs. When connecting Spike Relay Modules, use the right 3 pins of the Relay port. Be sure to
connect the cable so the black wire is on the indicated pin (on the right side of the connector). Shown
below is the Relay port pin-out to aid in the connection of a Multi-Speed Motor and/or Spike Relay
Modual to a Relay output.
Multi-Speed Motor Spike Relay Module
Connection Connection
Table 6: Relay Output Map
Relay
Port Shaft
Rotation PBASIC
Variable Alias PBASIC
Variable Pin
Location Wire
Color
RLY 1
CW RelayA.bit0 Relay1_fwd
Center Right
Red
RLY 1
CCW RelayA.bit1 Relay1_rev
Center Left
White
RLY 2
CW RelayA.bit2 Relay1_fwd
Center Right
Red
RLY 2
CCW RelayA.bit3 Relay1_rev
Center Left
White
RLY 3
CW RelayA.bit4 Relay1_fwd
Center Right
Red
RLY 3
CCW RelayA.bit5 Relay1_rev
Center Left
White
RLY 4
CW RelayA.bit6 Relay1_fwd
Center Right
Red
RLY 4
CCW RelayA.bit7 Relay1_rev
Center Left
White
+Battery
(Orange)
Ground
(Black)
Ground
(Black)
Rev/CCW
(White)
Fwd/CW
(Red)
Forward
(Red)
Reverse
(White)
Not Used