User's Manual

105 Radio/Serial Telemetry Module User Manual
Page 48 © March 2000
AI1 and AI2 represent the value for the two analogue inputs. Full scale input (20 mA) is displayed
as C000, 4mA is displayed as 4000, and 0ma is displayed as 2000. Analogue inputs are filtered
digitally with a time constant of 1 second, so a sudden change in the analogue input current will result
in a slower change in displayed analogue value, finally settling at the new value.
A guide to translate the displayed value to the analogue input current is provided below.
Add together the figures corresponding to each digit in each position to determine
the current (mA)
e.g. displayed value 3456 = 2.000+0.500+0.039+0.003
= 2.542mA
Digit Leftmost position Next position Next position Rightmost
position
0 - 0.000 0.000 0.000
1 - 0.125 0.008 0.000
2 0.000 0.250 0.016 0.001
3 2.000 0.375 0.023 0.001
4 4.000 0.500 0.031 0.002
5 6.000 0.625 0.039 0.002
6 8.000 0.750 0.047 0.003
7 10.000 0.875 0.055 0.003
8 12.000 1.000 0.063 0.004
9 14.000 1.125 0.070 0.004
A 16.000 1.250 0.078 0.005
B 18.000 1.375 0.086 0.005
C 20 1.500 0.094 0.006
D 22 1.625 0.102 0.006
E - 1.750 0.109 0.007
F - 1.875 0.117 0.007
VBATT is the current internally derived battery voltage. 4000 corresponds to 8 Volts, C000
represents 16 volts. A quicker method is use the calculation :
Battery voltage (volts) = ½ I + 6, where I is the mA value determined from the above table using
VBATT. For example, a value of VBATT of A000 gives an I value of 16mA from the above
table. The battery voltage corresponding to this is 14V (or ½ x 16 + 6).
105-2 Modules
Digital Inputs
DIN SETPNT PULSED
1234MSL123456 PIN1 PIN2 PIN3 PIN4
0000100111111 0000 0000 0000 0000