Serial UPS Control Cable for PowerMon Software

      CPU      <--------- CABLE --------> UPS
               1
        DCD<-- o-------+                 +---o |
                   +++  |          |      |     +- BATT. EMPTY
                   |R|  |    white |      |   o |
                   |1|  +--------- | -----+   |
               3   +++       green |          |
        TD --> o---+------------- | ---------   UPS - Switch
                  | |       yellow |          |
               4  | |   +--------- | -----+   |
        DTR--> o--+-   |          |      |   o |
                  |+++  |                 |     +- POWER ERROR
                  ||R|  |                 +---o |
                  ||2|  |  R1..R2 2x10K Ohm
               8  |+++  |         1% - 0.25W
        CTS<-- o--+----+
                 _|_
                 ---  10nF/400V
               5  |C1
  SG / GND --- o--+
                                  VENDOR supplied cable !
           DB-9 Connector

see >> SERIAL Port (RS-232)


Techn. description:

The Control-cable is included in SW-package. After programstart DTR signal goes high (+9 Vdc) DCD and CTS are forced high (R1-R2). Transmit Data is low (-9 Vdc) and routed to the UPS-BATT/POWER failure switches. If one (or both) of this switches is engaged (short) the negative TD signal should force DCD/CTS to low. The negative DCD/CTS will be recognized by software, and a (NOVELL) shutdown is initiated, after a customer defined time period.


  On some machines (e.g. PC 500 Server) you might have the problem, that this cable is not functioning, because the resistors R1/R2 have to high resistance (because DCD and CTS < 3Vdc), maybe resistors >= 1K2 up to 2K7 will work ok?


Back to  Jump to TOP-of-PAGE

Please see the LEGAL  -  Trademark notice.
Feel free - send a Email-NOTE  for any BUG on this page found - Thank you.