Wavetronix SmartSensor HD (101-0415) - User Guide - Manual (Page 87)

86 APPENDIX • SMARTSENSOR HD USER GUIDE
9-pin D connector and a null modem cable. To connect directly to a DCE device (such as a
modem), you will need a straight-through cable. Figure D.1 illustrates both of these cases.
Connector
Power
Wires
RS-485
Wires
OR
DTE Device (PC)
DCE Device (Modem)
Null Modem Cable
Straight-through Cable
Figure D.1 – Direct Serial Connections
Note
If you do not have the right type of RS-232 physical connection you will not be able
to connect using the SmartSensor Manager software. Since null modem cables and
straight-through cables look similar, you may want to label them. Alternatively, you
may want to use a null modem adapter instead of a null modem cable. If you do,
you can turn your straight-through cable into a null modem cable by attaching the
adapter on one end.
If you wish to connect the 9-conductor cable’s RS-485 wires directly to a PC or modem, this
will require that these devices natively support RS-485 communications. Often, modern
personal computers do not support RS-485 communications and support USB communi-
cations instead. If your computer only supports USB communications, you may want to use
a USB converter to make a direct connection.
Appendix E - Signaling Delays
Signaling delays vary depending on what equipment is used. These delays may affect deci-
sions about where to install the sensor in relation to other equipment in cases where timeli-
ness in communication is necessary. The following is information about SmartSensor HD
signaling delays.