Inputcircuitry; Reading The Comparatorsand The Gating Logic - Siemens SIMATIC S5 1P 243 Equipment Manual

3.6.2. Input Circuitry
Input circuitty for each comparator
22 k~
Analog signal
22 k~
Attention: When comparators are used to compare voltages, the circuit specific,
absolute hysteresis of approximately 4.4Y0 of the voltage difference
between comparator output (O V/5 V) and input COMP+ (O V to 10 V)
must be considered.
3.6.3 Reading the Comparators and the Gating Logic
The two comparators are addressed under module address +5. The data bits O to 3 contain infor-
mation about the current comparator status. The data bits are identified by the characters A, B, C,
and D.
Read module address +5
D7
1
Byte module address +7 not only specifies the analog input channel which is to be converted by
the ADC, but also specifies the status of the signals LOG and STROBE. The bit LOG switches the
M
+15 v
M ."=
M
1 1 1 D
Function Description
2.2 k~
+5 v
logic
output
Data bus
*routed to interrupt
DO
c B A
Xl 9 Pins 7/8
3 – 15