LAN Manager UPS Serial Port Pin Usage (76909)

SUMMARY

Most uninterruptible power supplies (UPSs) signal their status via contact closure or voltage changes on specific pins. LAN Manager uses this method to monitor the UPS.

The pins that LAN Manager uses are:

   CTS = Line fail
         (Power out)
   DCD = Low battery
   DTR = UPS shutdown
         (Signal from the server to the UPS to shut down)

Whether a signal is high or low to indicate a given state is dependent on the manufacturer. For more information, please see the UPS section of Appendix B in the "Microsoft LAN Manager Administrator's Reference" (see especially the VOLTLEVELS parameter), and the user's guide that came with the UPS.

MORE INFORMATION

Unfortunately, there is an IOCTL (I/O control) used to handle the types of signal changes a UPS sends that is not supported in COM0x.SYS; therefore, the UPSDRV.OS2 driver used by LAN Manager is required.

Note: The UPS service/driver defaults to COM1. If another communications port is being used, it must be specified when loading the driver in the CONFIG.SYS file. Change CONFIG.SYS from

   device=c:\lanman\drivers\upsdrv.os2

to the following

   device=c:\lanman\drivers\upsdrv.os2 /PORT:COMx

where x is the number of the COM port.