Operating instructions

30 Operating Instructions
2.7 Communication Interfaces
The static switch monitoring system includes two RS-232 communication ports, an optional
modem, an optional RS422 SiteScan Communications Port, and switch status contacts for remote
monitoring of the static switch. One of the RS-232 ports is intended for the connection to a local
terminal. The other RS-232 port is for connection to the optional modem. Connections to the com-
munication ports are made by wiring to terminal boards located in the monitoring system com-
partment located behind the operator control panel. Connection points are shown on the control
wiring interconnection drawing. Typical connections are shown in Figure 9. Contact Liebert Glo-
bal Services for assistance when attaching an external device to the static switch.
Data link requirements are Full Duplex Asynchronous RS-232 format. The terminal may be con-
figured as DTE or DCE, with a Baud rate of 2400. The baud rates are 1200 or 2400 with 8 Data
Bits, 1 Stop Bit, No Parity, and Handshaking is not required.
Local Terminal Port—This communication port can be used to send switch status and history
information to a local terminal in an RS-232 format. The Present Status screen is sent to this port
whenever a new alarm occurs. Commands for requesting other information and for changing the
date and time are shown in Table 2.
Modem Port—This communication port automatically dials the programmed phone number
when a designated alarm occurs. Automatic dial attempts are made to the first phone number at
periodic intervals for 30 minutes. After that time, auto dial attempts are made to the second
phone number at periodic intervals for the next 30 minutes. The process is repeated until success-
ful connection is made. Upon successful connection, the system transmits the Present Status
screen information, then hangs up. System status and history information can be requested and
date and time can be changed through the modem. The modem commands are shown in Table 2.
Table 2 Terminal/Modem Commands
Key(s) Function
A, return Displays the Present Status screen information.
^B, return Displays the Event History screens starting with the most recent frame.
C, return Displays the History Status screens starting with the most recent frame.
F (no return) A toggle switch command to stop and start data scrolling.
G, return Resets (unfreezes) the History Status buffer. (Do not reset the History Status buffer until
qualified personnel have reviewed its contents).
Q (no return) Interrupts (quits) the data output.
d mm/dd/yy, return Sets the date (month/day/year) of the monitoring system clock.
t hh:mm:ss, return Sets the time (hour:minute:second) of the monitoring system clock.
H, return Prompts the system to hang up the modem.
backspace Moves terminal cursor left to cancel previous entry.