Specifications

HYDROLOGICAL SERVICES

DL3 100-040 IMP

Issue 2: 15/11/2005

5.1.4 Communications Interface

The communications interface is very powerful and flexible, allowing for simple direct connection

to a PC through to modem connection and automatic dialling into and through a computer

network and dumping data onto a computer. The hardware interface is standard RS232, and

various software flags and parameters allow for the flexible operation. The logger can be woken

up remotely either by reception of Rx data or by assertion of carrier detect (DCD). Four baud

rates can be selected as well as hardware or Xon/Xoff handshaking.

5.1.5 Watchdog

The logger incorporates ‘watchdog’ circuitry within the microprocessor to automatically recover

from unforeseen software or noise indued failures. The action of a watchdog reset does not affect

previously recorded data or any set-up parameters including date and time.

5.1.6 Power Supply / Power Consumption

It is recommended to power the logger with one external 12 volt battery. Minimum voltage

11Vdc, Maximum voltage 14Vdc.

To conserve power, the logger normally functions in a ‘sleep’ mode. On receipt of an event the

logger ‘wakes up’ and performs the appropriate program tasks before returning to ‘sleep’.An

event is considered a contact closure, a communication input or a timer wakeup.

Hardware design facilitates simple battery replacement and protection against polarity reversal. A

separate battery compartment protects the logger electronics against possible battery leakage.

Power consumption calculations are specific to a Hydrological Services RRDL-3 logger and

DataPlex PSTN DPX-213 Hayes compatible modem.

Mode RRDL-3 DPX-213 Total

Operating 75 mA 80 mA

155 mA

Sleep 200 uA Nil

200 uA

Calculations are based on the following :-

24 interrogations daily, at 60 second call duration.

The DPX-213 operating mode is with front panel led indicators off and wake on ring

detect.

24 calls X 60 secs = 1440 secs, therefore current drain = 155 mA for 1440 secs

24 Hrs X 60 min X 60 secs = 86400 secs, therefore current drain = 200 uA for 86400secs

- 1440 secs

1440/86400 = 0.0167 or 1.67% (1.7%), therefore 1.7% @ 155 mA and 98.3% @ 200