NDC comm NDC-3 - Manual (Page 11)

Page 11 © 2005 Active Research Limited
Specifications
Parameter Conditions Min. Max. Unit
Supply
Supply voltage
8 35 V
Supply current (see note 1)
Supply voltage = 12v 26 30 mA
Supply voltage = 24v 16 18 mA
NMEA
Input voltage between +/-
Logical ‘1’/stop bit -15.0 0.5 V
Logical ‘0’/start bit 4.0 15.0 V
Input current
Maximum is under +35v overload
condition
2.0 30 mA
Differential input voltage
Required level for NMEA to be
detected
1.8 2.0 V
Output voltage between +/- and ground
(see note 2)
Logical ‘1’/stop bit 0.0 0.5 V
4.8 5.2 V
Output current (see note 2)
At maximum load, drive voltage
reduces to 2v
- 32 mA
Output short circuit current. 50 55 mA
Baud rate - fixed (see note 3) 4.8 kbit/sec
Data propagation delay 1.0 100 ms
RS-232
Input voltage range
-15 +15 V
Input voltage threshold
LOW 0.8 1.2 V
HIGH 1.7 2.8 V
Output voltage swing Loaded with 3κΩ to Ground ±5 ±9 V
Output resistance (RS232 Vout = ±2v) 300 Ohms
Output short circuit current
(Infinite duration)
±18 mA
Baud rate (see note 4) 38.4 kbit/sec
Data propagation delay 1.0 100 ms
General
Ambient temperature
-20 +70 °C
Table 2 – NDC-3 specifications
All specifications are taken with reference to an ambient temperature (T
A
) of +25°C.
Note:
1. Current consumption measured under no-load conditions
2. NMEA output is RS-485 compatible.
3. NMEA 0183 inputs and outputs on the NDC-3 are fixed to 4800 baud
4. RS232 baud rate is fixed at 38400 baud on the NDC-3