SECTION 4. EXTERNAL STORAGE PERIPHERALS

the RC35 by switching power through the DC power line of the SC92A/SC93A.

TABLE 4.3-1 Cassette RecorderSpecifications

Power

6 VDC (provided by

 

CR10 through SC92A or

 

SC93A); 4 AA size

 

batteries; 120 VAC/6

 

VDC adapter

Current Drain

200 mA typ./5 sec.,

while Recording

300 max.

Tape Length

C-60 recommended

Tape Quality

Normal bias, high quality

 

(e.g., TDK, Maxell)

External Inputs

Mic., DC In, Monitor, and

 

Remote

Operating

0° to +40°C

Temperature

 

POWER SUPPLY

The CR10's internal power supply will power the recorder during periods of data transfer, but will NOT be available to play, advance, or backup tapes. In order to perform these functions during setup and check-out operations, the recorder requires 4 alkaline AA batteries or the 120 VAC adapter.

OPERATING TEMPERATURE LIMITATIONS

The cassette recorder is recommended for use in an environmental operating temperature range of 0° to +40°C. Temperatures below 0°C may cause tape speed variation in excess of that which can be tolerated during playback. If the RC35 is outside the 0°C to 40°C range, data transferred may be unreadable.

VOLUME CONTROL

When recording data, the RC35's volume setting does not matter. The recorder is equipped with an automatic gain control which controls the recorded signal level. For playback, a mid- range volume setting is normally required.

CASSETTE TAPES

4-4

Normal bias, high quality cassette tapes are recommended for use with the recorder. The more expensive high bias chromium oxide tapes will NOT perform satisfactorily. Although the use of C-90 tapes is generally successful, Campbell Scientific recommends the use of C- 60 (30 minutes per side) cassettes. TDK, Maxell, and equivalent quality cassette tapes perform well and are readily available. Bargain- priced tapes have often performed poorly and are not recommended.

New tapes are often tightly wound, creating enough drag or pressure to cause the tape recorder to "pop" out of the record mode. This potential loss of data may be overcome by fast- forward/rewinding the entire tape before placing it in service.

4.3.2CASSETTE CONNECTOR INTERFACE CABLES

A cassette interface cable is required to connect the cassette recorder to the CR10. Two models are available. The SC92A is a WRITE ONLY interface. The SC93A is a READ/WRITE interface that allows the CR10 to load datalogger programs from tape in addition to writing data and programs. The SC93A is required only if special software exists in the datalogger PROM for transferring programs via tape (refer to Appendix B)

The SC92A and SC93A have a combination backshell circuit card and subminiature 9-pin D- type connector which attaches to the socket connector on the wiring panel. The other end of the SC92A has two plugs which are plugged into the POWER and MIC jacks on the recorder. The SC93A has three plugs which are plugged into the POWER, MIC and EAR (or MONITOR) jacks on the recorder. Both cables transform 12 V from the CR10 to 6 V for powering the recorder during periods of data transfer. Additional circuitry shapes the data signal waveform.

WARNING: The SC92/SC93 interfaces previously supplied with the 21X and CR7 dataloggers are not compatible with the CR10. The SC235 CR21 Cassette Connector Interface supplied with the CR21 datalogger is not compatible with the CR10. If the SC92, SC93, or SC235 interfaces are used with the CR10, the data on tape CANNOT be recovered!