Impulse 2108 - Manual (Page 11)

© Sealevel Systems, Inc. - 9 - SeaLINK+232.PC User Manual
Appendix C – Electrical Interface
RS-232
Quite possibly the most widely used communication standard is RS-232. This
implementation has been defined and revised several times and is often referred
to as RS-232 or EIA/TIA-232. The IBM PC computer defined the RS-232 port
on a 9 pin D sub connector and subsequently the EIA/TIA approved this
implementation as the EIA/TIA-574 standard. This standard is defined as the
9-Position Non-Synchronous Interface between Data Terminal Equipment and
Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange.
Both implementations are in wide spread use and will be referred to as RS-232 in
this document. RS-232 is capable of operating at data rates up to 20 Kbps at
distances less than 50 ft. The absolute maximum data rate may vary due to line
conditions and cable lengths. RS-232 is a single ended or unbalanced interface,
meaning that a single electrical signal is compared to a common signal (ground)
to determine binary logic states. The RS-232 and the EIA/TIA-574 specification
define two types of interface circuits, Data Terminal Equipment (DTE) and Data
Circuit-Terminating Equipment (DCE). The SeaLINK+232.PC is a DTE device.