optical coupler A device that converts electronic signals inside the PTC into
pulses of light that can be detected by an optical communication
station.
prompt Messages shown by the PTC that guide the operator through
the steps of a data collection program. Prompts vary for
different programs.
PTC Portable Tele-Transaction Computer . A battery-powered,
hand-held, programmable device used to collect, store, and
transmit data.
RAM Random access memory. In a PTC, RAM chips store the
program’s files and data entered by the operator.
RI Ring indicate signal. RI alerts a modem to a call waiting on the
attached telephone line.
RS-232 An Electronic Industries Association (EIA) standard that defines
the connector, connector pins, and signals used to transfer data
serially from one device to another.
RTS Request-to-send signal. RTS initiates the data transmission
sequence on a communication line between a modem and a
terminal device.
RXD Receive data signal. RXD indicates that a device is currently
receiving data.
software A stored program or set of programs that is loaded into RAM for
execution. Compare with hardware.
TCAL Telxon Common Application Language. Telxon’s proprietary
programming language for PTCs.
two-way
communication Exchange of information between two devices. After each block
of data, the receiving device sends a positive or negative
acknowledgment to the sending device.
TXD Transmit data signal. TXD indicates that a device is currently
transmitting data.
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