As many as 7 monitoring Caller ID units can be connected together into one serial port. Each unit has a line selector switch located on the rear panel. This switch is used to set up additional units for the appropriate line numbers. Each time the switch in depressed for 2 seconds the line numbers on the unit will increase by four. For example, the switch should be pressed once for the second unit to set it for lines 5 through 8. The switch should be pressed twice on the third unit to set it for lines 9 through 12. Additional unit line numbers can be set accordingly.

The switch will set line numbers up to 49 and then roll over to 1. Loss of power to the unit will not affect line numbers set by the switch. The line number set for channel 1 of each unit can be seen in the HyperTerminal program described in Appendix E, Using Hyperterminal in Windows to Monitor Unit. Within the main terminal screen, type a capital “V” (for version). The unit will respond with the version of the firmware, unit toggle settings, and the line number of Channel 1.

Use the supplied serial cable to connect unit #1 with unit #2. The cable attaches to the unit #1 port marked "To Next Unit" to the unit #2 port marked "To Computer." Unit #2 connects with unit #3 in the same manor.