Campbell SC32A, Справочное руководство

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Reference Manual
5
5.3.2 External Power Supply
Two situations require an external power supply for the RS232 side of the
SC32A:
1. The input logic levels required by the Data Receive line of the RS232 device
exceed the output level of the RTS and DTR lines.
2. The RTS and DTR lines which power the SC32A are absent from the cable
going to the RS232 device.
The most common external supply is a 6 or 12V DC battery. Any supply over 9V
must be connected to pin 15 only.
Connecting a non-current limited supply of greater than 9V to
pins 4 or 20 could cause permanent damage to the SC32A.
External power connections to the SC32A are given below:
SC32A 25-Pin Port External Power
Pin # Supply
4 and/or 20 or 15 +
1 and/or 7 -
Ensure that the grounds of the RS232 device and the external supply are tied
together.
Jumper
Figure 1 PCB Layout
CAUTION