User's Manual

Page 62 of 83

A Carrier Corp. Company

PART NUMBER T82002163

REV A

TempTale 4 (OKI TT4)

Communications

The Monitor has an Infrared optical interface as its primary means for communication to

the outside world. There are also provisions made on the PCB for a hard-wired

asynchronous 0 to +3 volt logic level output. On the optical port, an infrared

phototransistor is used to sense data being input to the device and an infrared LED is

used to transmit data out of the device. This interface will be used for communicating

between an external device (PC w/Interface Plus and TripStrip) and the Monitor. The

hard-wired connection is currently not used but is available for future peripherals.

Any peripheral device that plans to use this connection will be responsible for any

added circuitry that may be required such as voltage level translation, static

protection, drivers, etc. It will also be the peripheral devices responsibility to supply

any power that is needed to operate the added circuitry.

On both interfaces, the data will be transmitted asynchronously using standard RS232

serial protocol. This allows the monitor to connect to a standard RS232 serial port

with very little effort. The monitor UART is setup to receive/transmit data at 9600

Baud with 8 data bits, no parity bit and two stop bits. This can be seen in the diagram

below.