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vacon • 4
OPTBK AS-interface board
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1.2.2
AS-i board layout and connections
Both data and power are supplied on the two-wire cable. The DC power carries the AS-interface sig-
nal. The AS-interface signal and the voltage regulating circuitry of the power supply must be sep-
arated.
Do not ground the AS-interface negative (ASI N). Grounding the signal lines results in poor commu-
nication or completely lost communication. The typical AS-interface media is not shielded. If shield-
ing is necessary for the application, ground the shield in only one place.
The AS-interface power supply provides voltages in the 30VDC range (29.5-31.6 VDC). It is higher
than the industry standard nominal 24VDC to compensate for the voltage drop on the line as well
as the drop through the AS-interface IC chip.
Figure 1. OPTBK AS-interface option board.
OPTBK AS-interface terminals
Terminal
Signal
Technical information
1
ASI P
AS-int
2
ASI N
AS-interface -
3
ASI Supply P
Auxiliary output voltage (ASi voltage input - max 2.4V at
maximum output current)
4
ASI Supply N
GND of Auxiliary output voltage
Table 3. OPTBK AS-Interface terminals
