Campbell Scientific SC932C Interface - Manual (Page 11)

C-1
APPENDIX C. SPECIFICATIONS
Data rates: up to 38,400 baud (limited by
datalogger)
Size: 63 x 55 x 17mm (L x W x D), excluding
mating D connectors
Operating environment: -25°C to +50 °C, 0-
95% RH (non-condensing)
Connector pin assignments: see Tables C-1
and C-2
Power requirements: sources power from
datalogger 5V supply via 9-pin interface.
TYPICAL CURRENT CONSUMPTION
• <100 µA with no RS232 load and pin 11 not
connected
• 2.2 mA with RAD and no communication
• 9.3 mA with RAD, datalogger in
communications mode, but low
communications activity
• 10.2 mA with RAD, high communications
activity
Current consumption when driving other RS232
modems will vary with the number of lines
connected and the input impedance of the
inputs. With 3 inputs connected (DTR, RTS
and Tx from the SC932C), of the minimum 3k
Ω
input impedance, and high communications
activity the consumption may be up to 16mA.
RS232 OUTPUT LEVELS
• RTS 4.2 - 4.5V with 3kΩ load – quiescent
state (ME low)
• RTS full power 7 - 9V with 3kΩ load (ME
high)
• DTR 7.5 - 9.5V with 3kΩ load (8.8V typical
with RAD); short circuit current 30mA
typical
• Tx greater than ±5V with 3kΩ load
RS232 INPUT THRESHOLDS RX AND RI
• Input low 0.8V minimum
• Input high 2.4V maximum
• Input resistance 5KΩ
PIN 11, POWER CONTROL INPUT
THRESHOLDS
• Input low 1.3V maximum (normal power
mode)
• Input high 3.5V maximum (to enable high
power mode)
• Input resistance greater than 10kΩ
• Maximum input voltage 20V
TIME-OUTS
• Minimum RING IN pulse width to generate
a ring signal to the datalogger is 20µs
• Minimum delay between ME going low and
RING IN enable is 0.5s (1s typical)
EMC SPECIFICATION
• Emissions BSEN 55022-1: 1995
• Immunity BSEN 50082-1: 1992