DOCUMENT:Q102711  25-AUG-1993  [W_NT]
TITLE   :INF: How to Create a UPS Cable for the APC Smart-UPS
PRODUCT :Windows NT
PROD/VER:3.10
OPER/SYS:WINDOWS
KEYWORDS:

 
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The information in this article applies to:
 
 - Microsoft Windows NT operating system, version 3.1
 - Microsoft Windows NT Advanced Server, version 3.1
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The APC Smart-UPS series models 900, 900XL, 1250, and 2000 systems
include a standard RS-232 line failure output and UPS shutdown input.
The low battery signal, however, is not a standard RS-232 signal and
requires special configuration for use with Windows NT.
 
For RS-232 outputs and inputs, the line failure, low battery, and UPS
shutdown signals can be connected from the UPS to one of the computers
RS-232 (serial) ports. Because the low battery signal generated by the
APC Smart-UPS is an open collector output, it must be pulled up to a
common reference voltage by means of a pullup resistor.
 
Following is the configuration for a cable that can be used with the
APC Smart-UPS series, including the implementation of the pullup
resistor.
 
   DB9 9 Pin Female Connector       DB9 9 Pin Male Connector
    (to PC serial port)              (to UPS connector)
          Pin #5------ Ground ----------Pin #4
          Pin #8------ Power Failure--- Pin #2
          Pin #4------ UPS Shutdown---- Pin #1
          Pin #1------ Low Battery----- Pin #5 --[10k ohm]-- Pin #8
 
The above diagram indicates that Pin #5 on the PC serial port should
be connected directly to pin 4 on the UPS side, pin 8 to pin 2, pin 4
to pin 1, and pin 1 to pin 5. In addition, pins 5 and 8 on the same
side (the UPS side) have a 10k ohm (10,000 ohm) resistor connected
between them. This resistor serves to pull the voltage on this
non-RS-232 output high until an actual low voltage is generated by a
low battery condition.
 
With the above cable, the following polarities should be set in the
UPS section of the Control Panel:
 
   Power failure signal: Positive
   Low battery signal:   Negative
   Remote UPS shutdown:  Positive
 
REFERENCES
==========
 
American Power Conversion Smart UPS 900, 900XL, 1250 & 2000 Owners
Manual
 
The APC Smart-UPS is manufactured by American Power Conversion, a
vendor independent of Microsoft; we make no warranty, implied or
otherwise, regarding this products' performance or reliability.
 
Additional reference words: 3.10
KBCategory:
KBSubcategory: hrdwr

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Copyright Microsoft Corporation 1993.