Siemens SIMATIC S5-90U System Manual page 483

S5-90U/S5-95U
Function
The module consists of two independent down counters with isolated inputs and outputs. It counts
input signals up to a frequency of 500 Hz from a set value down to the value "0". When zero is
reached, the 24-V DC output of the module is energized.
At the same time, a green LED on the module lights up and the input signal (I x.0 or I x.1) is set to
"1".
The setpoint (0 to 999) can be entered via the three-digit thumbwheel switches on the front panel
of the module.
The input voltage ranges can be set for 5 V DC or 24 V DC on rocker switches on the front panel.
Channel 0
Channel 1
5 V DC (TTL)
Figure 16-5. Setting the Input Voltage Range on the Counter Module (500 Hz)
Installation
The counter module is plugged into a bus unit like any other module (see Chapter 3).
Wiring
See schematic diagram.
EWA 4NEB 812 6115-02b
Channel 0
Channel 1
24 V DC
Function Modules
16-15