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Table 2. XM-8DR-BRD terminals
Terminal
Function
+12V
Positive power supply contact, 12V DC
GND
Ground
IO1
RACS Clock&Data comm. bus (CLK terminal)
IO2
RACS Clock&Data comm. bus (DTA terminal)
IN1-IN8
Input lines
NO
Relay output (NO)
COM
Relay common terminal
NC
Relay output (NC)
In the fig. 2 there is shown connection diagram for XM-8DR and PR402DR access controller. The
communication is performed by means of RACS Clock&Data bus.
Fig. 2 Connection of XM-8DR-BRD expander with PR402DR controller
2.2. LED indicators
XM-8DR is equipped with ten LED indicators i.e. LED Link, LED Power and 8 indicators associated
with relays. When LED indicator at REL1..REL8 inscription is on then corresponding relay is
activated. LED Link signals the communication between expander and master device (controller)
while LED Power can signal 4 states according to table. 3.
Table 3. LED Power signalling
State
Description
Steady light
Normal operation
Infrequently flashing light (2Hz)
No communication
Frequently flashing light (10Hz)
Too low supply voltage
