Input And Output Signals; Counter Pulses At The Cu1 And Cu2 Input - Siemens SIMATIC S5 Manual

Standard Function Counter
3

Input and Output Signals

You control the functionality of the counter via the digital inputs of the IP 265 and via data that is
transferred to the IP 265 from the CPU via the process image of the outputs (PIQ)
3.1

Counter Pulses at the CU1 and CU2 Input

This input is a direct link with your process. The counter pulses to be processed by the program are
applied here.
In the standard function, two inputs per counter channel are provided for the counter pulses:
• One counter input for 24 V signals up to a limit frequency of 10 kHz.
• One high-speed counter input for 5 V differential signals to RS422A with a limit frequency of
58 kHz.
Timing of the counter pulses at the CU1 and CU2 input (5 V differential input)
The following conditions must be observed for the sensor signals:
A
min. 8.6 µs min. 8.6 µs
A-N
min. 8.6 µs min. 8.6 µs
This results in a minimum pulse time of 17.2 µs. The maximum input frequency is then 58 kHz.
The mark/space ratio is variable. However, the minimum time limits must not be violated.
EWA 4NEB 812 6131-02
Input and Output Signals
3-1