Installation manual

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SIMPLEX Fault Assistance Guide RevA
29 April 2009
1.1.5 Mapnet Loop Power Supply Calibrations
It is possible to recalibrate the MAPNET Loop Power Supply (excluding IDNet) output to
possibly overcome a number of issues. This Calibration should NOT normally be attempted
unless there are some site issues that are occurring and not easily diagnose/rectified.
You should consider the Calibration option if
 There are numerous, or intermittent numerous Bad Answers and No Answers
occurring on a loop that has been 100% correctly addressed and wired/terminated
correctly
 The MAPNET loop voltage is not fluctuating between 36-38 Volts
NOTE: The MAPNET loop voltage will fluctuate normally as it is transmitting
digital data at all times when powered
 The MAPNET loop length guidelines and restrictions are not adhered to, and there is
no other solution available. (i.e. the loop length exceeds the recommended
maximum of 1000m)
To alter the operating voltage of the MAPNET
Cards Power Supply you will need to locate
potentiometer ‘R2.’ Adjust R2 until the DC
Voltage across the loop is approximately
36.5V ± 100mV (i.e. approximately 36-38 Volts).
!