Impulse 2102 - Manual (Page 15)

Appendix C - Electrical Interface
Sealevel Systems SeaLINK+485 Page 12
Appendix C - Electrical Interface
RS-530
RS-530 (a.k.a. EIA-530) compatibility means that RS-422 signal levels are met,
and the pin-out for the DB-25 connector is specified. The EIA (Electronic
Industry Association) created the RS-530 specification to detail the pin-out, and
define a full set of modem control signals that can be used for regulating flow
control and line status. The RS-530 specification defines two types of interface
circuits, Data Terminal Equipment (DTE) and Data Circuit-Terminating
Equipment (DCE). The Sealevel Systems adapter is a DTE interface.
RS-422
The RS-422 specification defines the electrical characteristics of balanced
voltage digital interface circuits. RS-422 is a differential interface that defines
voltage levels and driver/receiver electrical specifications. On a differential
interface, logic levels are defined by the difference in voltage between a pair of
outputs or inputs. In contrast, a single ended interface, for example RS-232,
defines the logic levels as the difference in voltage between a single signal and a
common ground connection. Differential interfaces are typically more immune
to noise or voltage spikes that may occur on the communication lines.
Differential interfaces also have greater drive capabilities that allow for longer
cable lengths. RS-422 is rated up to 10 Megabits per second and can have
cabling 4000 feet long. RS-422 also defines driver and receiver electrical
characteristics that will allow 1 driver and up to 32 receivers on the line at once.
RS-422 signal levels range from 0 to +5 volts. RS-422 does not define a
physical connector.