Siemens SIMATIC S5-100U System Manual page 433

S5-100U
Function
The counter module can be used as an up-counter or as an up/down counter for a position decoder.
The counting pulses are supplied by a sensor that you can connect to the 15-pin subminiature D
female connector of the module. You can choose from two types of sensors that fulfill the following
requirements:
• 5-V error voltages according to RS 422 (up to 500 kHz)
• 24-V signals (up to 25 kHz)
As additional inputs, the module has an enable input and a reference input.
By using the STEP 5 program, you can assign two setpoints via the I/O bus. Once the counter
status reaches one of these values, the respective output completes the circuit at terminal block
(Q 0 or Q 1). The status of the outputs is displayed in the diagnostic byte.
You can also read the following values by using the STEP 5 program:
• The updated count
• The diagnostic byte
You can preselect the following items on the operating mode switch:
• The function mode
• The position resolution
• The input voltage range of the sensor
PD
SV
Figure 15-7. Switch Positions on the Operating Mode Switch
EWA 4NEB 812 6120-02b
2×
4×
24 V
Function Modules
Position decoding (PD)
Counter (C)
Pos. resolution single
Pos. resolution double
Pos. resolution quadruple
not allowed
Sensor connection 5 V
Sensor connection 24 V
15-19