Siemens Simatic S7-1500 CPU 1512C-1 PN User Manual page 28

Product overview
2.2 Hardware properties and firmware functions
Properties of the analog inputs
The 5 inputs of the analog on-board I/O module have the following properties:
Property
Resolution: 16 bits includ-
ing sign
Integrated types of meas-
uring
Configurable diagnostics
Hardware interrupt
28
Description
A CPU processes information exclusively in digital
format. An ADC (analog-to-digital converter) integrated
into the analog on-board I/O module therefore converts
the analog value into a bit pattern. For the CPU, this
conversion always returns a 16-bit word for SIMATIC
products. The ADC used digitalizes the analog signal
and approximates its value with a stepped curve. The
resolution specifies the number of increments of the
analog value along this stepped curve here.
Controllers are only capable of processing analog val-
ues in the form of bit patterns. For this purpose, trans-
ducers which can be connected to the analog module
measure physical variables such as pressure or tem-
perature. This analog value is measured by the analog
input module in the form of the measurement types
current, voltage or resistance. The analog on-board I/O
module supports the following measurement types on
the following channels.
Voltage measurement type can be set individually
•
for channel 0 to 3
Current measurement type can be set individually
•
for channel 0 to 3
Resistor measurement type can be set for channel 4
•
Thermal resistor measurement type can be set for
•
channel 4
The analog on-board I/O module can diagnose errors.
The module reports the diagnosed state to the CPU
using a diagnostics error interrupt. Different types of
diagnostics are available that you can parameterize
channel-granularly.
You can react to process events (such as nega-
tive/positive exceeding of specific limits) through the
configuration of a hardware interrupt. Hardware inter-
rupts can be parameterized channel-granularly.
Additional information
Chapter Analog value pro-
•
cessing
Analog value processing function
•
manual
(http://support.automation.sieme
ns.com/WW/view/en/67989094)
Chapter Parameters of the analog
on-board I/O (Page 122)
Chapter Parameters of the ana-
•
log on-board I/O (Page 122)
Chapter Structure of a data rec-
•
ord for input channels of the ana-
log on-board I/O (Page 166)
STEP 7 online help
•
CPU 1512C-1 PN (6ES7512-1CK01-0AB0)
Manual, 12/2017, A5E40898741-AA