Location Of The Signals In The Process I/O Images; Oring And Evaluating Signals - Siemens SIMATIC S5 Manual

Standard Function Counter
3.4

Location of the Signals in the Process I/O Images

The location of the inputs and outputs on the module is described in Section 2. The locations in the
process I/O image are as follows:
Location of the control signals in the signal byte:
PIQ
Bit 7
Location of the outputs in the output byte:
PII
Bit 7
Only the control signals and the output signal of channel 1 are decisive for the cascade function.
Output Q2 is always "0" in the cascade function.
3.5

ORing and Evaluating Signals

There are two signal inputs for different signals of the standard function counter:
• Hardware inputs
• PIQ data
These "inputs" are ORed with each other internally. They are always active simultaneously and can
be driven independently of each other.
This means, for example:
• The CU counter pulses can be routed either via a 24 V digital input or a 5 V digital output.
• The signal for resetting the counter channel (RSC) can be given either via a 24 V digital input or
via a bit in the PIQ of the CPU.
The outputs are active at the hardware output and in a bit in the PII simultaneously. The negated
output signal has no equivalent in the PII.
Table 3-1 ORing the Interfaces of the Standard Counter Function
24 V
Signals 5 V DI
DI
CD • •
RSQ •
RSC •
GATE •
Q
Q\
EWA 4NEB 812 6131-02
RSC2 RSC1 RSQ2 RSQ1 GATE2 GATE1
24 V
PIQ PII
DQ
•
•
•
• •
•
Input and Output Signals
Byte No. 6
Bit 0
Byte No. 6
Q2 Q1
Bit 0
Signal Evaluation
Edge-Triggered
Rising Edge
Rising Edge
Rising Edge
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Value-Triggered
"1"
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3-3