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©DSan Corporation
Limitimer® Rackmount User Guide
Serial Communications
Limitimer communicates with signal lights and client timers via high speed serial connection.
Limitimer Rackmount translates the serial data into easy-to-read and easy-to-send plain-text format and
adds information about the phase lights and other status indicators to the message so that touch panel
controller can simulate the Limitimer console. The text format is available on the RS-232 serial port.
RS-232 protocol uses separate wires for transmit and receive. Limitimer uses a half-
duplex RS-485 protocol where transmit and receive happen on the same wire, but at
separate times in the message. An internal RS-232—RS-485 adapter handles the
interface between Limitimer and touch panel controllers. An external adapter (TP-
2000x) is also available as an accessory.
The touch panel controller port should be configured at 9600 baud with 8 data bits, no
parity, and one stop bit.
The message on the RS-232 port incorporates a checksum.
The Touch Panel API is found in a separate document "LimitimerTouchPanel_API.pdf" on the Limitimer
Rackmount flash drive.
