Campbell Scientific SC932A 9-Pin to 9-Pin RS-232 Interface - Manual (Page 7)

SC932A 9-Pin to RS-232-DCE Interface
3
Electrical
The SC932A uses power from the +5 V line on the 9-pin interface connected to
the datalogger.
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: 0.9 in (2.3 cm)
Width: 1.6 in (4.1 cm)
Length: 3 in (7.6 cm)
Weight: 1.6 oz (45.4 g)
Environmental
Temperature: -25 to +50 o C
Humidity: up to 95% non-condensing
3. Installation
Connect the SC932A to the RS-232 device and to the datalogger with the SC12
9-pin cable (included). If the device has a 25-pin connector, a 9-pin female to
25-pin male adaptor is required (CSI PN 15751).
Proper transient protection should be installed to protect the computer and
datalogger in areas where damage due to lightning is possible. If this is a RAD
modem application, see Section 4.2.
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
(PN 15770) that includes the SC932A, the 9- to 25-pin adaptor (PN 15751),
and a mounting bracket (PN 6282). 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 built by RAD*.
* SRM - 5A RAD Modem
RAD Data Communications Inc.
900 Corporate Drive
Mahwah, NJ 07430
Tel: (201) 529-1100
Fax: (201) 529-5777
Email: [email protected]
http://www.rad.com
For transmission, the RAD modem uses a cable made of 2 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