Xylem XL Series H-522 - Plus - Manual (Page 24)

2-10 Hardware Options and Installation
XL™ Series
Figure 2-8 Event Counter Input
Figure 2-9 Event Counter Circuit
2.2.10 Event Counter Input
Pins 10 and 11 of the terminal block provide connection points for the digital event counter
input.
This input is normally used with a tipping bucket rain gauge. However, it can be used for other
counter type of applications also. Transient protection is provided for this input to prevent
damage from static discharge or over voltage conditions. This input is pulled high through a 51K
Ohm resistor allowing a switch closure to ground to activate the counter. Figure 2-9 shows a
simplified circuit for this input.