SC932A CS I/O to RS-232-DCE Interface
3
Data Rates:
The SC932A will support baud rates up to
115,200 bps.
Electrical:
The SC932A uses power from the +5 V line on the
9-pin interface connected to the data logger.
Additional current (up to 10 mA) from the 5 V
supply may be used by the RS-232 device
connected to the SC932A.
Physical
Height:
2.3 cm (0.9 in)
Width:
4.1 cm (1.6 in)
Length:
7.6 cm (3 in)
Weight:
45.4 g (1.6 oz)
Environmental
Temperature:
–25 to 50 °C
Humidity:
Up to 95% non-condensing
Compliance Documents:
View at
3. Installation
Connect the SC932A to the RS-232 device and to the data logger with the
SC12 9-pin cable. If the device has a 25-pin connector, a 9-pin female to
25-pin male adaptor is required.
The SC932A ships with four screw jacks. They can be installed on both sides
of each connector, allowing screws to be used to secure cables to the device.
Proper transient protection should be installed to protect the computer and data
logger in areas where damage due to lightning is possible. If this is a RAD
modem application, see Section
RAD Modem Wiring and Grounding
(p. 4)
.
4. RAD Modem Application
The SC932A is frequently used with a short range modem to communicate
across a 4-wire, unconditioned dedicated line. Campbell Scientific offers a kit
that includes the SC932A, the 9- to 25-pin adaptor, and a mounting bracket.
The bracket will mount the RAD, SC932A and adaptor to the back plate in a
Campbell Scientific enclosure. This section describes using a short range
asynchronous modem, SRM-5A RAD modem.
For transmission, the RAD modem uses a cable made of two pairs of twisted
wires with a shield. Data rates up to 9600 bps are possible. The low voltage
transmission levels minimize cross-talk between adjacent lines within the same
cable. Data are transmitted and received at a balanced impedance, providing
excellent immunity to circuit noise. TABLE
gives the data rate possible for
several ga
u
ge cables across several distances.
